@import url('https://fonts.googleapis.com/css2?family=Inter:wght@350;400;450;500;550;600&display=swap');

/* ============================================
   PREMIUM SCIENTIFIC TOOL DESIGN SYSTEM
   Inspired by Apple, Google, Anthropic
   ============================================ */

:root {
    /* Premium Accent - Refined Blue-Violet */
    --accent: #6366f1;
    /* Indigo 500 */
    --accent-hover: #4f46e5;
    /* Indigo 600 */
    --accent-light: #818cf8;
    /* Indigo 400 */
    --accent-muted: rgba(99, 102, 241, 0.12);
    --accent-subtle: rgba(99, 102, 241, 0.06);

    /* Semantic Colors - Softer, Premium */
    --success: #10b981;
    /* Emerald 500 */
    --success-muted: rgba(16, 185, 129, 0.1);
    --warning: #f59e0b;
    /* Amber 500 */
    --warning-muted: rgba(245, 158, 11, 0.1);
    --danger: #ef4444;
    /* Red 500 */
    --danger-muted: rgba(239, 68, 68, 0.1);

    /* Neutral Palette - Warmer, Softer Grays */
    --white: #ffffff;
    --gray-25: #fafafa;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Text Hierarchy - Refined Contrast */
    --text: #111827;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --text-subtle: #9ca3af;

    /* Light Mode Surfaces */
    --bg-page: #f9fafb;
    --bg-gradient: radial-gradient(circle at top center, #ffffff 0%, #f3f4f6 100%);
    --glass-bg: #ffffff;
    /* Solid white, no transparency */
    --glass-border: #e5e7eb;
    /* Solid gray, no transparency */
    --card-bg: #ffffff;
    --card-bg-gradient: linear-gradient(145deg, #ffffff 0%, #f9fafb 100%);
    --card-border: #e5e7eb;
    /* Solid gray */
    --card-hover-bg: #ffffff;

    --bg: var(--white);
    --bg-subtle: var(--gray-50);
    --bg-muted: var(--gray-100);
    --border: var(--gray-200);
    --border-subtle: var(--gray-100);
    --border-strong: var(--gray-300);

    /* Premium Shadows - Soft, Layered (Apple-inspired) */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 15px rgba(99, 102, 241, 0.3);
    --shadow-focus: 0 0 0 3px rgba(99, 102, 241, 0.3);

    /* Radius - Premium Curves */
    --radius-xs: 0.25rem;
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;

    /* Spacing Scale - Generous Whitespace */
    --space-0: 0px;
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.5rem;
    --space-6: 2rem;
    --space-7: 2.5rem;
    --space-8: 3rem;
    --space-9: 4rem;

    /* Animation - Smooth, Premium Feel */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.45, 0, 0.55, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
    --duration-fast: 150ms;
    --duration-normal: 250ms;
    --duration-slow: 400ms;
    --transition: var(--duration-normal) var(--ease-out);
    --transition-fast: var(--duration-fast) var(--ease-out);
    --transition-slow: var(--duration-slow) var(--ease-out);

    /* Toggle switch knob */
    --toggle-knob-color: #FFFFFF;
    --toggle-knob-shadow: 0 1px 3px rgba(0, 0, 0, 0.15), 0 1px 2px rgba(0, 0, 0, 0.1);

    /* Premium layered shadows - Apple-inspired */
    --shadow-card:
        0 0 0 1px rgba(0, 0, 0, 0.03),
        0 2px 4px rgba(0, 0, 0, 0.05),
        0 12px 24px rgba(0, 0, 0, 0.05);
    --shadow-card-hover:
        0 0 0 1px rgba(0, 0, 0, 0.03),
        0 4px 8px rgba(0, 0, 0, 0.06),
        0 24px 48px rgba(0, 0, 0, 0.08);
    --shadow-elevated:
        0 0 0 1px rgba(0, 0, 0, 0.02),
        0 4px 8px rgba(0, 0, 0, 0.04),
        0 16px 32px rgba(0, 0, 0, 0.06);
    --shadow-accent-glow: 0 4px 20px -4px rgba(99, 102, 241, 0.3);

    /* Glassmorphism */
    --glass-bg-translucent: rgba(255, 255, 255, 0.8);
    --glass-border-translucent: rgba(255, 255, 255, 0.5);
    --glass-blur: 12px;

    /* Dot grid background */
    --dot-color: rgba(0, 0, 0, 0.035);
}

/* ============================================
   GLOBAL MICRO-INTERACTIONS
   ============================================ */

::selection {
    background: var(--accent-muted);
    color: var(--accent);
}

/* Tactile button feedback */
button:active,
.segment-btn:active,
.theme-toggle:active {
    transform: scale(0.96);
}

/* Smooth focus rings */
*:focus-visible {
    outline: none;
    box-shadow: 0 0 0 3px var(--accent-muted);
    transition: box-shadow var(--duration-fast) var(--ease-out);
}

/* Dark Mode - Premium Dark */
[data-theme="dark"] {
    /* Accent - Lighter for dark backgrounds */
    --accent: #818cf8;
    /* Indigo 400 */
    --accent-hover: #a5b4fc;
    /* Indigo 300 */
    --accent-light: #c7d2fe;
    /* Indigo 200 */
    --accent-muted: rgba(129, 140, 248, 0.15);
    --accent-subtle: rgba(129, 140, 248, 0.08);

    /* Semantic Colors - Adjusted for dark */
    --success: #34d399;
    /* Emerald 400 */
    --success-muted: rgba(52, 211, 153, 0.15);
    --warning: #fbbf24;
    /* Amber 400 */
    --warning-muted: rgba(251, 191, 36, 0.15);
    --danger: #f87171;
    /* Red 400 */
    --danger-muted: rgba(248, 113, 113, 0.15);

    /* Text Hierarchy - Dark mode */
    --text: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #9ca3af;
    --text-subtle: #6b7280;

    /* Dark Mode Surfaces */
    --bg-page: #0f172a;
    /* Slate 900 */
    --bg-gradient: radial-gradient(circle at top center, #1e293b 0%, #0f172a 100%);
    --glass-bg: #0f172a;
    /* Solid dark */
    --glass-border: #334155;
    /* Solid border */
    --card-bg: #1e293b;
    /* Slate 800 */
    --card-bg-gradient: linear-gradient(145deg, #1e293b 0%, #0f172a 100%);
    --card-border: #334155;
    /* Solid border */
    --card-hover-bg: #334155;
    /* Slate 700 */

    --bg: #1e293b;
    --bg-subtle: #334155;
    --bg-muted: #475569;
    --border: #334155;
    /* Solid */
    --border-subtle: #1e293b;
    /* Solid */
    --border-strong: #475569;
    /* Solid */

    /* Dark Shadows - Subtle, layered */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 15px rgba(129, 140, 248, 0.2);
    --shadow-focus: 0 0 0 3px rgba(129, 140, 248, 0.2);

    /* Toggle switch knob - dark mode */
    --toggle-knob-color: #F3F4F6;
    --toggle-knob-shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);

    /* Premium layered shadows - dark mode */
    --shadow-card:
        0 0 0 1px rgba(255, 255, 255, 0.03),
        0 2px 4px rgba(0, 0, 0, 0.2),
        0 12px 24px rgba(0, 0, 0, 0.25);
    --shadow-card-hover:
        0 0 0 1px rgba(255, 255, 255, 0.05),
        0 4px 8px rgba(0, 0, 0, 0.25),
        0 24px 48px rgba(0, 0, 0, 0.35);
    --shadow-elevated:
        0 0 0 1px rgba(255, 255, 255, 0.03),
        0 4px 8px rgba(0, 0, 0, 0.2),
        0 16px 32px rgba(0, 0, 0, 0.3);
    --shadow-accent-glow: 0 4px 20px -4px rgba(129, 140, 248, 0.4);

    /* Glassmorphism - dark mode */
    --glass-bg-translucent: rgba(15, 23, 42, 0.8);
    --glass-border-translucent: rgba(255, 255, 255, 0.08);

    /* Dot grid background - dark mode */
    --dot-color: rgba(255, 255, 255, 0.02);
}

/* High Contrast Mode */
[data-high-contrast="true"] {
    /* IBM Design Language Colorblind Safe Palette inspired */

    /* Success -> Blue (instead of Green) */
    --success: #648fff;
    --success-muted: rgba(100, 143, 255, 0.15);

    /* Warning -> Gold/Orange (High visibility) */
    --warning: #ffb000;
    --warning-muted: rgba(255, 176, 0, 0.15);

    /* Danger -> Magenta/Purple (instead of Red) */
    --danger: #dc267f;
    --danger-muted: rgba(220, 38, 127, 0.15);

    /* Accent -> Teal (distinct from others) */
    --accent: #785ef0;
    --accent-hover: #5e46d0;
    --accent-light: #9480f4;
    --accent-muted: rgba(120, 94, 240, 0.25);
    /* Increased opacity */

    /* HIGH CONTRAST OVERRIDES */
    --text: #000000;
    /* Pure black for max contrast */
    --text-secondary: #1f2937;
    /* Darker gray */
    --text-muted: #374151;
    /* Much darker than normal muted */
    --text-subtle: #4b5563;

    --border: #9ca3af;
    /* Darker borders */
    --border-subtle: #d1d5db;
    --border-strong: #6b7280;
}

/* Dark Mode + High Contrast adjustments */
[data-theme="dark"][data-high-contrast="true"] {
    /* Adjust brightness for dark mode if necessary,
       but the above palette is generally safe for dark backgrounds too.
       Slight tweaks for better contrast on dark: */

    --success: #78a9ff;
    --warning: #ffc133;
    --danger: #e85e9c;

    /* HIGH CONTRAST DARK MODE */
    --text: #ffffff;
    /* Pure white */
    --text-secondary: #f3f4f6;
    /* Very light gray */
    --text-muted: #e5e7eb;
    /* Light gray */
    --text-subtle: #d1d5db;

    --border: #6b7280;
    /* Lighter borders for dark mode */
    --border-subtle: #4b5563;
    --border-strong: #9ca3af;

    --bg-subtle: #0f172a;
    /* Darker background for contrast against text */
}

/* ============================================
   BASE
   ============================================ */

*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-size: 15px;
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    font-size: 1rem;
    line-height: 1.6;
    font-weight: 400;
    letter-spacing: -0.011em;
    color: var(--text);
    background: var(--bg-page);
    background-image: var(--bg-gradient);
    min-height: 100vh;
    font-feature-settings: 'cv11', 'ss01';
    position: relative;
    overflow-x: hidden;
}

/* Subtle dot grid background pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(
        circle at 1px 1px,
        var(--dot-color) 1px,
        transparent 0
    );
    background-size: 24px 24px;
    pointer-events: none;
    opacity: 0.6;
    z-index: -1;
}

/* Premium selection styling */
::selection {
    background: var(--accent-muted);
    color: var(--text);
}

/* ============================================
   LAYOUT
   ============================================ */

.container {
    max-width: 1320px;
    margin: 0 auto;
    padding: var(--space-6) var(--space-7);
}

.main-layout {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
}

.main-content-grid {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: var(--space-6);
    align-items: start;
}

/* ============================================
   HEADER
   ============================================ */

.header {
    background: var(--glass-bg-translucent);
    backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    border-radius: var(--radius-xl);
    padding: var(--space-4) var(--space-5);
    box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    border: 1px solid var(--glass-border-translucent);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-5);
    margin-bottom: var(--space-4);
    position: relative;
    transition: all var(--transition);
}

.header:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--border-strong);
    transform: translateY(-1px);
}

.header-content {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.header h1 {
    font-size: 1.25rem;
    font-weight: 650;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--text) 0%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 0;
}

[data-theme="dark"] .header h1 {
    background: linear-gradient(135deg, #FFFFFF 0%, var(--gray-300) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-subtitle {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--text-muted);
    margin: 0;
    padding-left: var(--space-4);
    border-left: 1px solid var(--border);
    letter-spacing: -0.01em;
}

/* ============================================
   CARDS & PANELS
   ============================================ */

.input-sidebar {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    padding: var(--space-5);
    box-shadow: var(--shadow-elevated);
    border: 1px solid var(--card-border);
    position: sticky;
    top: var(--space-5);
    z-index: 10;
    transition: box-shadow var(--transition), border-color var(--transition);
}

.input-sidebar:hover {
    box-shadow: var(--shadow-card-hover);
    border-color: var(--border);
}

.sidebar-section-title {
    font-size: 0.6875rem;
    font-weight: 550;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: var(--space-3);
    margin-top: 0;
}

.sidebar-section-title:not(:first-child) {
    margin-top: var(--space-5);
    padding-top: var(--space-4);
    border-top: 1px solid var(--border-subtle);
}

.calculator-section {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--card-border);
    transition: box-shadow var(--transition), border-color var(--transition);
}

.calculator-section:hover {
    box-shadow: var(--shadow-card-hover);
    border-color: var(--border);
}

.calculator-main {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

/* ============================================
   FORM ELEMENTS
   ============================================ */

.input-group {
    margin-bottom: var(--space-4);
}

.input-group:last-child {
    margin-bottom: 0;
}

/* Remove spin buttons from number inputs */
.input-group input[type="number"]::-webkit-inner-spin-button,
.input-group input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.input-group input[type="number"] {
    -moz-appearance: textfield;
    appearance: textfield;
}

.input-group label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 6px;
    letter-spacing: -0.01em;
    transition: color var(--transition-fast);
}

.input-group:focus-within label {
    color: var(--accent);
}

.input-group input,
.input-group select,
.geometry-dropdown-compact {
    width: 100%;
    height: 40px;
    padding: 0 var(--space-4);
    font-size: 0.9375rem;
    font-family: inherit;
    font-feature-settings: 'tnum';
    font-weight: 400;
    color: var(--text);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    transition:
        border-color var(--transition-fast),
        box-shadow var(--transition-fast),
        background-color var(--transition-fast);
}

.input-group input::placeholder {
    color: var(--text-subtle);
}

.input-group input:hover,
.input-group select:hover,
.geometry-dropdown-compact:hover {
    border-color: var(--border-strong);
    background: var(--bg);
}

.input-group input:focus,
.input-group select:focus,
.geometry-dropdown-compact:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow:
        var(--shadow-focus),
        0 0 0 3px var(--accent-subtle),
        0 0 20px -5px var(--accent-muted);
    background: var(--bg);
}

.input-group small {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 6px;
    letter-spacing: -0.01em;
}

/* Select styling */
.input-group select,
.geometry-dropdown-compact {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23737373' d='M6 8L2 4h8z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 12px;
    padding-right: 32px;
    cursor: pointer;
    appearance: none;
}

/* Radio Buttons - Premium Segmented Control */
.radio-button-group {
    display: flex;
    gap: 0;
    margin-top: 8px;
    background: var(--bg-subtle);
    border-radius: var(--radius-sm);
    padding: 3px;
    border: 1px solid var(--border-subtle);
}

.radio-option {
    flex: 1;
    position: relative;
}

.radio-option input[type="radio"] {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.radio-label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 32px;
    padding: 0 var(--space-3);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    border-radius: calc(var(--radius-sm) - 2px);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.radio-label:hover {
    color: var(--text);
    background: var(--bg-muted);
}

.radio-option input[type="radio"]:checked+.radio-label {
    color: var(--text);
    background: var(--bg);
    box-shadow: var(--shadow-sm);
}

.radio-option input[type="radio"]:focus-visible+.radio-label {
    box-shadow: var(--shadow-focus);
}

.radio-icon {
    font-size: 0.875rem;
    line-height: 1;
    opacity: 0.8;
}

/* Toggle Switch - Premium iOS-style */
.toggle-container {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.toggle-switch {
    position: relative;
    width: 44px;
    height: 24px;
    flex-shrink: 0;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background: var(--bg-muted);
    border-radius: 12px;
    transition: background var(--transition);
    border: 1px solid var(--border);
}

.toggle-slider::before {
    content: "";
    position: absolute;
    width: 18px;
    height: 18px;
    left: 2px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--toggle-knob-color);
    border-radius: 50%;
    transition: left var(--transition);
    box-shadow: var(--toggle-knob-shadow);
}

input:checked+.toggle-slider {
    background: var(--success);
    border-color: var(--success);
}

input:checked+.toggle-slider::before {
    left: calc(100% - 20px);
}

/* Toggle focus state */
.toggle-switch input:focus-visible+.toggle-slider {
    box-shadow: var(--shadow-focus);
}

/* Inline toggle */
.toggle-label-inline {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: background var(--transition);
    flex-shrink: 0;
}

.toggle-label-inline:hover {
    background: var(--bg-muted);
}

.toggle-label-inline input {
    width: 14px;
    height: 14px;
    accent-color: var(--accent);
    margin: 0;
}

.toggle-text-inline {
    font-weight: 500;
}

.toggle-label-text {
    font-size: 0.8125rem;
}

.advanced-toggle-group {
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--border-subtle);
}

/* ============================================
   GEOMETRY PANELS
   ============================================ */

.geometry-panel {
    display: none;
}

.geometry-panel.active {
    display: block;
}

#geometry-dimensions {
    margin-top: 6px;
    margin-bottom: 2px;
}

#geometry-dimensions .geometry-panel {
    animation: panelFadeIn 0.15s var(--ease-out);
}

@keyframes panelFadeIn {
    from {
        opacity: 0;
        transform: translateY(4px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#geometry-dimensions .thin-film-info,
#geometry-dimensions .infinite-rod-info {
    padding: var(--space-3) 0;
    text-align: center;
}

#geometry-dimensions .limit-case-header {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 4px;
}

#geometry-dimensions .limit-case-description {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin: 0;
}

/* ============================================
   RESULTS
   ============================================ */

.result {
    color: var(--text);
    line-height: 1.5;
}

.section-header-compact {
    color: var(--text);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    border-bottom: 1px solid var(--border);
    padding-bottom: 6px;
    margin-bottom: 8px;
    margin-top: var(--space-4);
}

.section-description {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-bottom: 10px;
    line-height: 1.5;
}

/* Demagnetization Summary */
.demagnetization-summary {
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: var(--space-3);
    margin-bottom: 10px;
}

.demag-header {
    font-size: 0.6875rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    text-align: center;
    margin-bottom: var(--space-4);
}

.demag-values-enhanced {
    display: flex;
    justify-content: space-around;
}

.demag-item-enhanced {
    text-align: center;
    flex: 1;
}

.demag-item-enhanced strong {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 4px;
}

.demag-value-clickable {
    display: inline-block;
    font-size: 1.1rem;
    font-weight: 600;
    font-family: inherit;
    font-feature-settings: 'tnum';
    color: var(--text);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.demag-value-clickable:hover {
    background: var(--bg-muted);
}

/* Axis Labels */
.axis-label-small {
    display: inline-block;
    font-size: 0.625rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.02em;
    margin-top: 6px;
    padding: 3px 8px;
    border-radius: 10px;
}

.axis-label-small.easy-axis {
    color: var(--success);
    background: var(--success-muted);
}

.axis-label-small.hard-axis {
    color: var(--danger);
    background: var(--danger-muted);
}

.axis-label-small.intermediate-axis {
    color: var(--text);
    background: transparent;
    border: 1px solid var(--border);
    /* Add subtle border for definition */
}

/* Property Cards - Premium Style */
.critical-properties-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
    margin-bottom: var(--space-4);
}

.property-card {
    background: var(--card-bg);
    background-image: var(--card-bg-gradient);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    transition:
        transform var(--transition),
        box-shadow var(--transition),
        border-color var(--transition);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-card);
    animation: cardFadeIn 0.4s var(--ease-out) backwards;
}

@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Skip entry animation when updating results (use pulse instead) */
.is-updating .property-card {
    animation: none;
}

.property-card:hover {
    border-color: var(--accent-muted);
    background: var(--card-hover-bg);
    transform: translateY(-3px);
    box-shadow: var(--shadow-card-hover), var(--shadow-accent-glow);
}

.property-card:hover .property-symbol {
    color: var(--accent);
}

/* Result update pulse animation */
.property-card.result-updated,
.is-updating .property-card.result-updated {
    animation: resultPulse 0.6s var(--ease-out);
}

.result-updated .main-value {
    animation: valueHighlight 0.8s var(--ease-out);
}

@keyframes resultPulse {
    0% {
        box-shadow: var(--shadow-card), 0 0 0 0 var(--accent-muted);
    }
    40% {
        box-shadow: var(--shadow-card), 0 0 0 4px var(--accent-muted);
    }
    100% {
        box-shadow: var(--shadow-card), 0 0 0 0 transparent;
    }
}

@keyframes valueHighlight {
    0% {
        background-color: var(--accent-subtle);
        border-radius: var(--radius-sm);
    }
    100% {
        background-color: transparent;
    }
}

/* Demagnetization summary pulse */
.demagnetization-summary.result-updated {
    animation: resultPulse 0.6s var(--ease-out);
}

/* Energy table pulse */
.energy-breakdown-table.result-updated {
    animation: resultPulse 0.6s var(--ease-out);
}

/* Input Header */
.input-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 4px;
}

/* Segmented Control - Premium Style */
.segmented-control {
    display: flex;
    background: var(--bg-subtle);
    padding: 3px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-subtle);
}

.segment-btn {
    border: none;
    background: transparent;
    padding: 6px 12px;
    font-size: 0.75rem;
    font-family: inherit;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: calc(var(--radius-sm) - 2px);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.segment-btn:hover {
    color: var(--text);
    background: var(--bg-muted);
}

.segment-btn.active {
    background: var(--bg);
    color: var(--text);
    box-shadow: var(--shadow-sm), 0 0 12px -2px var(--accent-subtle);
    font-weight: 550;
}

.segment-btn:focus-visible {
    box-shadow: var(--shadow-focus);
    z-index: 1;
}

/* Small variant for property card headers */
.segmented-control-sm {
    padding: 2px;
}

.segment-btn-sm {
    padding: 3px 8px;
    font-size: 0.6875rem;
}

.property-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 6px;
}

.property-header h5 {
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin: 0;
}

.property-symbol {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-muted);
    font-style: italic;
    font-family: inherit;
    transition: color var(--transition-fast);
}

.property-value {
    text-align: center;
    padding: 4px 0;
}

.main-value {
    display: inline;
    font-size: 1.125rem;
    font-weight: 600;
    font-feature-settings: 'tnum';
    color: var(--text);
}

.unit {
    display: inline;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-left: 2px;
}

.alt-unit {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 3px;
}

.property-formula {
    background: var(--bg-subtle);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    padding: 6px 10px;
    text-align: center;
    font-size: 0.8125rem;
    margin-top: 8px;
}

.property-value-clickable {
    cursor: pointer;
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    transition: background var(--transition);
}

.property-value-clickable:hover {
    background: var(--bg-muted);
}

.property-description {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: block;
    margin-top: 2px;
}

/* Preferred direction indicator */
.preferred-direction {
    display: inline-block;
    font-size: 0.9rem;
    /* Larger */
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 4px;
    margin-top: 4px;
    color: var(--white);
    /* White text */
    white-space: nowrap;
}

.preferred-direction.pma {
    background: transparent;
    color: var(--text);
    padding-left: 0;
}

.preferred-direction.ipa {
    background: transparent;
    color: var(--text);
    padding-left: 0;
}

.keff-value {
    color: var(--text);
}

/* ============================================
   ENERGY ANALYSIS
   ============================================ */

.effective-anisotropy-summary {
    margin-top: 0;
}

.energy-breakdown-table {
    margin: 0;
    overflow-x: auto;
}

.energy-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.energy-table thead {
    background: var(--bg-muted);
}

.energy-table th {
    padding: 6px 8px;
    text-align: center;
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    color: var(--text);
    border-bottom: 1px solid var(--border);
    background: var(--bg-subtle);
}

.energy-table td {
    padding: 10px 12px;
    text-align: center;
    border-bottom: 1px solid var(--border);
    font-family: inherit;
    /* Use Inter */
    font-feature-settings: 'tnum';
    font-size: 0.9rem;
}

.energy-table tbody tr:last-child td {
    border-bottom: none;
}

.energy-table tbody tr:hover {
    background: var(--bg-subtle);
}

.energy-state-description {
    display: block;
    font-size: 0.6875rem;
    color: var(--text-muted);
    font-weight: normal;
    margin-top: 2px;
}

.energy-axis-cell {
    font-weight: 600;
    color: var(--text);
}

.energy-value-cell {
    font-family: inherit;
    font-feature-settings: 'tnum';
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.energy-total-cell {
    font-family: inherit;
    font-feature-settings: 'tnum';
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text);
    background: var(--bg-muted);
}

.energy-row-easy {
    background: var(--success-muted);
}

.energy-row-hard {
    background: var(--danger-muted);
}

.energy-badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 10px;
    font-size: 0.625rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.02em;
    margin-left: 8px;
}

.energy-badge.easy {
    background: var(--success);
    color: white;
}

.energy-badge.hard {
    background: var(--danger);
    color: white;
}

/* ============================================
   THEORY COLLAPSIBLE
   ============================================ */

.theory-collapsible {
    margin-top: var(--space-2);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    overflow: hidden;
    max-width: 100%;
}

.theory-collapsible.collapsed .theory-content {
    display: none;
}

.theory-collapsible.collapsed .theory-toggle {
    transform: rotate(-90deg);
}

.theory-header {
    cursor: pointer;
    padding: var(--space-3) var(--space-4);
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
    background: var(--bg);
    transition: background var(--transition);
}

.theory-header:hover {
    background: var(--bg-muted);
}

.theory-title {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text);
}

.theory-toggle {
    font-size: 0.75rem;
    color: var(--text-muted);
    transition: transform var(--transition);
}

.theory-content {
    padding: var(--space-4);
    overflow-x: auto;
    max-width: 100%;
    word-break: break-word;
}

.theory-section {
    margin-bottom: var(--space-4);
}

.theory-section:last-child {
    margin-bottom: 0;
}

.theory-subtitle {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    margin: 0 0 8px 0;
}

.theory-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.theory-formula-box {
    padding: var(--space-3) var(--space-4);
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    overflow-x: auto;
    max-width: 100%;
}

.theory-formula-grid {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 6px 12px;
    align-items: baseline;
}

.theory-formula-grid strong {
    color: var(--text);
    font-size: 0.8125rem;
}

.theory-list {
    margin: 8px 0 0 20px;
    padding: 0;
    font-size: 0.875rem;
}

.theory-list li {
    margin-bottom: 4px;
}

.theory-highlight {
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    margin: 8px 0;
    font-size: 0.875rem;
}

.theory-highlight.blue {
    background: var(--accent-muted);
    border-left: 2px solid var(--accent);
}

/* ============================================
   THEME TOGGLE - Premium Button
   ============================================ */

.theme-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    height: 36px;
    padding: 0 var(--space-4);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.theme-toggle:hover {
    color: var(--text);
    background: var(--bg-muted);
    border-color: var(--border-strong);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.theme-toggle:active {
    transform: translateY(0) scale(0.98);
    box-shadow: var(--shadow-xs);
}

.theme-toggle:focus-visible {
    box-shadow: var(--shadow-focus);
    border-color: var(--accent);
}

/* Share button copied state */
.theme-toggle.share-copied {
    background: var(--success);
    border-color: var(--success);
    color: white;
    animation: shareCopiedPulse 0.3s var(--ease-spring);
}

.theme-toggle.share-copied:hover {
    background: var(--success);
    border-color: var(--success);
    transform: none;
    box-shadow: var(--shadow-sm);
}

.theme-toggle.share-copied .theme-toggle-icon {
    color: white;
}

@keyframes shareCopiedPulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.theme-toggle-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    opacity: 0.8;
}

/* ============================================
   FOOTER - Minimal, Premium
   ============================================ */

.site-footer {
    text-align: center;
    padding: var(--space-8) 0 var(--space-6);
    margin-top: var(--space-8);
    font-size: 0.8125rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-subtle);
}

.site-footer p {
    line-height: 1.6;
    margin: 0;
    letter-spacing: -0.01em;
}

.site-footer p+p {
    margin-top: 6px;
}

.site-footer a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.site-footer a:hover {
    color: var(--accent);
}

/* ============================================
   CITATIONS
   ============================================ */

.formula-source {
    margin-top: var(--space-5);
    padding-top: var(--space-4);
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 0.8125rem;
    color: var(--text-muted);
}

.formula-source a,
.citation-link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.formula-source a:hover,
.citation-link:hover {
    color: var(--accent);
    text-decoration: underline;
}

.formula-source a:active,
.citation-link:active {
    color: var(--accent-hover);
}

/* ============================================
   NOTES & ERRORS
   ============================================ */

.explanation-note {
    background: var(--success-muted);
    border-left: 3px solid var(--success);
    padding: var(--space-3) var(--space-4);
    margin: var(--space-4) 0;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-size: 0.8125rem;
    color: var(--text);
}

.error-message-box {
    background: var(--danger-muted);
    border-radius: var(--radius-md);
    padding: var(--space-4);
    margin: var(--space-4) 0;
}

.error-message-header {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--danger);
    margin-bottom: 6px;
}

.error-message-text {
    font-size: 0.8125rem;
    color: var(--text);
}

.error-message-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: var(--space-2);
}

/* ============================================
   MATHJAX
   ============================================ */

.MathJax {
    color: var(--text) !important;
}

.MathJax_Display {
    margin: 0.4em 0 !important;
    overflow-x: auto;
}

mjx-container {
    font-size: 100% !important;
}

/* ============================================
   UTILITIES
   ============================================ */

.text-secondary {
    color: var(--text-secondary);
}

/* ============================================
   RESPONSIVE - Fluid, Premium
   ============================================ */

@media (max-width: 1100px) {
    .container {
        padding: var(--space-5) var(--space-5);
    }

    .main-content-grid {
        grid-template-columns: 300px 1fr;
        gap: var(--space-5);
    }
}

@media (max-width: 900px) {
    .container {
        padding: var(--space-4);
    }

    .main-content-grid {
        grid-template-columns: 1fr;
        gap: var(--space-5);
    }

    .input-sidebar {
        position: static;
        padding: var(--space-5);
    }

    .critical-properties-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .container {
        padding: var(--space-3);
        width: 100%;
        box-sizing: border-box;
    }

    .header {
        padding: var(--space-3);
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-3);
        border-radius: var(--radius-lg);
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .header-subtitle {
        padding-left: 0;
        border-left: none;
        font-size: 0.8125rem;
    }

    .header h1 {
        font-size: 1.125rem;
    }

    /* Header buttons - display in a row, icons only */
    .header-actions {
        display: flex !important;
        gap: 6px !important;
        justify-content: flex-end;
        flex-wrap: wrap;
    }

    .theme-toggle {
        padding: 8px 10px;
        font-size: 0.75rem;
        min-height: 36px;
    }

    /* Hide button text on small screens, show only icons */
    .theme-toggle span {
        display: none;
    }

    .theme-toggle-icon {
        width: 18px;
        height: 18px;
    }

    .calculator-section {
        padding: var(--space-4);
        border-radius: var(--radius-lg);
    }

    .input-sidebar {
        padding: var(--space-4);
        border-radius: var(--radius-lg);
        width: 100%;
    }

    .main-content-grid {
        display: flex;
        flex-direction: column;
        gap: var(--space-4);
    }

    .critical-properties-grid {
        grid-template-columns: 1fr;
        gap: var(--space-3);
    }

    .property-card {
        padding: var(--space-4);
        overflow: hidden;
    }

    /* Prevent value overflow on mobile */
    .main-value {
        font-size: 1.25rem;
        word-break: break-all;
        overflow-wrap: anywhere;
    }

    .property-symbol {
        font-size: 0.875rem;
    }

    .property-label {
        font-size: 0.75rem;
    }

    /* Demagnetization N values - stack vertically on mobile */
    .demag-values-enhanced {
        flex-direction: column;
        gap: var(--space-3);
    }

    .demag-item-enhanced {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: var(--space-2) 0;
        border-bottom: 1px solid var(--border-subtle);
    }

    .demag-item-enhanced:last-child {
        border-bottom: none;
    }

    .demag-item-enhanced strong {
        margin-bottom: 0;
    }

    .demag-value-clickable {
        font-size: 1rem;
    }

    /* Unit switching buttons - smaller on mobile */
    .segmented-control-sm {
        gap: 2px;
    }

    .segment-btn-sm {
        padding: 2px 6px;
        font-size: 0.625rem;
    }

    .radio-button-group {
        flex-direction: column;
        gap: 0;
    }

    /* Ensure touch targets are at least 44px */
    .radio-label {
        min-height: 44px;
    }

    .segment-btn {
        min-height: 44px;
        padding: 10px 16px;
    }

    .toggle-switch {
        width: 50px;
        height: 28px;
    }

    .toggle-slider::before {
        width: 22px;
        height: 22px;
    }

    input:checked+.toggle-slider::before {
        left: calc(100% - 24px);
    }

    /* Sidebar section titles */
    .sidebar-section-title {
        font-size: 0.625rem;
    }

    /* Input labels - prevent ugly breaks on mobile */
    .input-group label {
        font-size: 0.75rem;
        white-space: nowrap;
    }

    /* Keep inline MathJax in labels on same line */
    .input-group label mjx-container {
        display: inline !important;
        overflow: visible !important;
    }

    /* Theory section mobile fixes */
    .theory-collapsible {
        margin-top: var(--space-2);
    }

    .theory-content {
        padding: var(--space-3);
    }

    .theory-formula-box {
        padding: var(--space-2) var(--space-3);
        font-size: 0.8125rem;
    }

    .theory-formula-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .theory-text {
        font-size: 0.8125rem;
    }

    .theory-subtitle {
        font-size: 0.8125rem;
    }

    /* MathJax overflow handling */
    mjx-container {
        overflow-x: auto !important;
        max-width: 100% !important;
        display: block !important;
    }
}

/* ============================================
   ACCESSIBILITY - Premium Focus States
   ============================================ */

*:focus-visible {
    outline: none;
    box-shadow: var(--shadow-focus);
}

/* Ensure links get proper focus styling */
a:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-radius: var(--radius-xs);
}

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    /* Hide dot grid for reduced motion users */
    body::before {
        display: none;
    }

    .theme-toggle.share-copied {
        animation: none;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border: rgba(0, 0, 0, 0.2);
        --border-subtle: rgba(0, 0, 0, 0.15);
        --border-strong: rgba(0, 0, 0, 0.3);
    }

    [data-theme="dark"] {
        --border: rgba(255, 255, 255, 0.2);
        --border-subtle: rgba(255, 255, 255, 0.15);
        --border-strong: rgba(255, 255, 255, 0.3);
    }
}

/* ============================================
   PRINT
   ============================================ */

@media print {

    .theme-toggle,
    .advanced-toggle-group {
        display: none;
    }

    * {
        animation: none !important;
        transition: none !important;
    }

    body {
        background: white;
        color: #000;
        font-size: 10pt;
    }

    .container {
        max-width: 100%;
        padding: 0;
    }

    .main-content-grid {
        display: block;
    }

    .input-sidebar {
        position: static;
        page-break-after: always;
        background: #f5f5f5;
        border: 1px solid #ddd;
    }

    .calculator-section,
    .header {
        box-shadow: none;
        border: 1px solid #ddd;
        background: white;
    }

    .property-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }

    a {
        text-decoration: underline;
        color: #000;
    }

    /* Only show URLs for external links */
    a[href^="http"]::after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
        color: #666;
    }

    /* Don't show URL for mailto links */
    a[href^="mailto"]::after {
        content: none;
    }
}

/* Tooltips - Premium Style */
.tooltip-container {
    position: relative;
    display: inline-flex;
    align-items: center;
    margin-left: 8px;
    vertical-align: middle;
}

.tooltip-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: var(--bg-subtle);
    color: var(--text-muted);
    font-size: 9px;
    font-weight: 500;
    font-family: inherit;
    text-transform: none;
    cursor: help;
    border: 1px solid var(--border-subtle);
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.tooltip-icon:hover {
    background: var(--accent-muted);
    color: var(--accent);
    border-color: var(--accent);
}

.tooltip-text {
    visibility: hidden;
    width: 260px;
    max-width: 90vw;
    background-color: var(--gray-900);
    color: var(--gray-100);
    text-align: left;
    text-transform: none;
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-4);
    position: absolute;
    z-index: 100;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    opacity: 0;
    transition: opacity var(--transition-fast), transform var(--transition-fast);
    font-size: 0.8125rem;
    font-weight: 400;
    line-height: 1.6;
    letter-spacing: -0.005em;
    box-shadow:
        0 4px 6px -1px rgba(0, 0, 0, 0.1),
        0 10px 15px -3px rgba(0, 0, 0, 0.15),
        0 20px 25px -5px rgba(0, 0, 0, 0.1);
    pointer-events: none;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.tooltip-text::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -6px;
    border-width: 6px;
    border-style: solid;
    border-color: var(--gray-900) transparent transparent transparent;
}

.tooltip-container:hover .tooltip-text {
    visibility: visible;
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ============================================
   ANIMATIONS - Premium, Smooth
   ============================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.98);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }

    100% {
        background-position: 200% 0;
    }
}

.calculator-section {
    animation: fadeInScale 0.5s var(--ease-out) forwards;
}

/* Stagger animation for property cards */
.property-card:nth-child(1) {
    animation-delay: 0ms;
}

.property-card:nth-child(2) {
    animation-delay: 60ms;
}

.property-card:nth-child(3) {
    animation-delay: 120ms;
}

/* Smooth scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

[data-theme="dark"] ::-webkit-scrollbar-thumb {
    background: var(--gray-600);
}

[data-theme="dark"] ::-webkit-scrollbar-thumb:hover {
    background: var(--gray-500);
}

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */

.toast-container {
    position: fixed;
    bottom: var(--space-6);
    left: 50%;
    transform: translateX(-50%);
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-5);
    background: var(--gray-900);
    color: var(--gray-100);
    border-radius: var(--radius-lg);
    box-shadow:
        0 4px 12px rgba(0, 0, 0, 0.15),
        0 16px 32px rgba(0, 0, 0, 0.2);
    font-size: 0.875rem;
    font-weight: 500;
    pointer-events: auto;
    animation: toastSlideIn 0.3s var(--ease-spring) forwards;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.toast.toast-exit {
    animation: toastSlideOut 0.2s var(--ease-out) forwards;
}

.toast-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.toast-success {
    background: linear-gradient(135deg, var(--gray-900) 0%, #064e3b 100%);
    border-color: var(--success);
}

.toast-success .toast-icon {
    color: var(--success);
}

.toast-error {
    background: linear-gradient(135deg, var(--gray-900) 0%, #7f1d1d 100%);
    border-color: var(--danger);
}

.toast-error .toast-icon {
    color: var(--danger);
}

.toast-info {
    background: linear-gradient(135deg, var(--gray-900) 0%, #1e3a5f 100%);
    border-color: var(--accent);
}

.toast-info .toast-icon {
    color: var(--accent-light);
}

@keyframes toastSlideIn {
    from {
        opacity: 0;
        transform: translateY(16px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes toastSlideOut {
    from {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
    to {
        opacity: 0;
        transform: translateY(-8px) scale(0.95);
    }
}

/* Dark mode toast adjustments */
[data-theme="dark"] .toast {
    background: var(--gray-800);
    border-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .toast-success {
    background: linear-gradient(135deg, var(--gray-800) 0%, #064e3b 100%);
}

[data-theme="dark"] .toast-error {
    background: linear-gradient(135deg, var(--gray-800) 0%, #7f1d1d 100%);
}

[data-theme="dark"] .toast-info {
    background: linear-gradient(135deg, var(--gray-800) 0%, #1e3a5f 100%);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .toast {
        animation: none;
        opacity: 1;
    }
    .toast.toast-exit {
        animation: none;
        opacity: 0;
    }
}