/* ═══════════════════════════════════════════════
   MugTuon Learning Hub & Cafe — Design System
   Notion-inspired, minimal, premium SaaS
   ═══════════════════════════════════════════════ */

/* ── CSS Reset ── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* ── Brand Colors ── */
    --color-primary: #543020;
    --color-primary-dark: #3d2218;
    --color-primary-light: #6b4332;
    --color-secondary: #55433b;
    --color-warm: #bda79e;
    --color-warm-light: #d4c4bc;
    --color-warm-lighter: #ebe3df;
    --color-accent: #004239;
    --color-accent-light: #367267;
    --color-accent-lighter: #4a9488;
    --color-white: #ffffff;

    /* ── Neutrals ── */
    --color-bg: #fafaf9;
    --color-surface: #ffffff;
    --color-surface-hover: #f7f5f3;
    --color-border: #e8e3df;
    --color-border-light: #f0ece9;
    --color-text: #1a1612;
    --color-text-secondary: #6b5e54;
    --color-text-muted: #9b8e84;
    --color-text-inverse: #ffffff;

    /* ── Semantic ── */
    --color-success: #1a7a5c;
    --color-success-bg: #ecf7f3;
    --color-warning: #b8860b;
    --color-warning-bg: #fdf6e3;
    --color-error: #c53030;
    --color-error-bg: #fef2f2;
    --color-info: #2563eb;
    --color-info-bg: #eff6ff;

    /* ── Typography ── */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    --leading-tight: 1.2;
    --leading-normal: 1.5;
    --leading-relaxed: 1.65;

    --weight-normal: 400;
    --weight-medium: 500;
    --weight-semibold: 600;
    --weight-bold: 700;

    /* ── Spacing ── */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    --space-32: 8rem;

    /* ── Radius ── */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    --radius-full: 9999px;

    /* ── Shadows ── */
    --shadow-xs: 0 1px 2px rgba(84, 48, 32, 0.04);
    --shadow-sm: 0 1px 3px rgba(84, 48, 32, 0.06), 0 1px 2px rgba(84, 48, 32, 0.04);
    --shadow-md: 0 4px 6px -1px rgba(84, 48, 32, 0.06), 0 2px 4px rgba(84, 48, 32, 0.04);
    --shadow-lg: 0 10px 15px -3px rgba(84, 48, 32, 0.06), 0 4px 6px rgba(84, 48, 32, 0.03);
    --shadow-xl: 0 20px 25px -5px rgba(84, 48, 32, 0.08), 0 8px 10px rgba(84, 48, 32, 0.04);

    /* ── Transitions ── */
    --ease-default: cubic-bezier(0.4, 0, 0.2, 1);
    --duration-fast: 150ms;
    --duration-normal: 250ms;
    --duration-slow: 400ms;

    /* ── Layout ── */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1200px;
    --container-2xl: 1400px;
    --sidebar-width: 260px;
    --header-height: 64px;
}

/* ── Dark Mode ── */
[data-theme="dark"] {
    --color-primary: #d4a88c;
    --color-primary-dark: #c49478;
    --color-primary-light: #e0bfac;
    --color-secondary: #c4b5ad;
    --color-warm: #6b5e54;
    --color-warm-light: #4a3f38;
    --color-warm-lighter: #2a2420;
    --color-accent: #4a9488;
    --color-accent-light: #5aada0;
    --color-accent-lighter: #367267;

    --color-bg: #1a1612;
    --color-surface: #252019;
    --color-surface-hover: #302920;
    --color-border: #3d342c;
    --color-border-light: #332c25;
    --color-text: #ece5df;
    --color-text-secondary: #b0a49a;
    --color-text-muted: #7d7068;
    --color-text-inverse: #1a1612;

    --color-success: #3dbb96;
    --color-success-bg: #1a2e27;
    --color-warning: #d4a017;
    --color-warning-bg: #2e2610;
    --color-error: #e05555;
    --color-error-bg: #2e1a1a;
    --color-info: #5b8def;
    --color-info-bg: #1a2240;

    --shadow-xs: 0 1px 2px rgba(0,0,0,0.2);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.3), 0 2px 4px rgba(0,0,0,0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.3), 0 4px 6px rgba(0,0,0,0.15);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.4), 0 8px 10px rgba(0,0,0,0.2);

    color-scheme: dark;
}

[data-theme="dark"] .auth-page__visual {
    background: linear-gradient(135deg, #1a1612 0%, #2a2420 100%);
}
[data-theme="dark"] .card, [data-theme="dark"] .dashboard-card {
    background: var(--color-surface);
}
[data-theme="dark"] img { opacity: 0.92; }

/* ── Animations ── */
@keyframes xp-pulse {
    0% { transform: scale(1); box-shadow: none; }
    50% { transform: scale(1.03); box-shadow: 0 0 20px rgba(0,66,57,0.2); }
    100% { transform: scale(1); box-shadow: none; }
}
.xp-pulse { animation: xp-pulse 0.8s ease-out; }

/* ── Base ── */
html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--color-text);
    background-color: var(--color-bg);
    overflow-x: hidden;
    min-height: 100vh;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--duration-fast) var(--ease-default);
}

a:hover {
    color: var(--color-accent-lighter);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
    font-size: inherit;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* ── Container ── */
.container {
    width: 100%;
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container--narrow {
    max-width: var(--container-md);
}

.container--wide {
    max-width: var(--container-2xl);
}

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: var(--weight-semibold);
    line-height: var(--leading-tight);
    color: var(--color-text);
}

h1 { font-size: var(--text-4xl); letter-spacing: -0.025em; }
h2 { font-size: var(--text-3xl); letter-spacing: -0.02em; }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

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

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-5);
    font-weight: var(--weight-medium);
    font-size: var(--text-sm);
    line-height: 1;
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) var(--ease-default);
    white-space: nowrap;
    user-select: none;
}

.btn--primary {
    background: var(--color-primary);
    color: var(--color-text-inverse);
}

.btn--primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn--accent {
    background: var(--color-accent);
    color: var(--color-text-inverse);
}

.btn--accent:hover {
    background: var(--color-accent-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn--outline {
    border: 1.5px solid var(--color-border);
    color: var(--color-text);
    background: var(--color-surface);
}

.btn--outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: var(--color-surface-hover);
}

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

.btn--ghost:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
}

.btn--lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-base);
    border-radius: var(--radius-lg);
}

.btn--sm {
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-xs);
}

.btn--full {
    width: 100%;
}

.btn--icon {
    padding: var(--space-3);
    border-radius: var(--radius-md);
}

/* ── Cards ── */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    transition: all var(--duration-normal) var(--ease-default);
}

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

.card--elevated {
    box-shadow: var(--shadow-sm);
}

.card--interactive:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.card--accent {
    border-color: var(--color-accent);
    border-width: 2px;
}

/* ── Form Elements ── */
.form-group {
    margin-bottom: var(--space-5);
}

.form-label {
    display: block;
    font-size: var(--text-sm);
    font-weight: var(--weight-medium);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2);
}

.form-input {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    color: var(--color-text);
    transition: all var(--duration-fast) var(--ease-default);
    outline: none;
}

.form-input:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(0, 66, 57, 0.1);
}

.form-input::placeholder {
    color: var(--color-text-muted);
}

.form-input--error {
    border-color: var(--color-error);
}

.form-hint {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    margin-top: var(--space-1);
}

.form-error {
    font-size: var(--text-xs);
    color: var(--color-error);
    margin-top: var(--space-1);
}

/* ── Badges ── */
.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: 2px var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--weight-medium);
    border-radius: var(--radius-full);
    line-height: 1.5;
}

.badge--primary { background: rgba(84,48,32,0.1); color: var(--color-primary); }
.badge--accent { background: rgba(0,66,57,0.1); color: var(--color-accent); }
.badge--success { background: var(--color-success-bg); color: var(--color-success); }
.badge--warning { background: var(--color-warning-bg); color: var(--color-warning); }
.badge--error { background: var(--color-error-bg); color: var(--color-error); }

/* ── Stats ── */
.stat {
    text-align: center;
}

.stat__value {
    font-size: var(--text-3xl);
    font-weight: var(--weight-bold);
    color: var(--color-text);
    line-height: 1;
}

.stat__label {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin-top: var(--space-1);
}

/* ── Avatar ── */
.avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--color-warm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--weight-semibold);
    color: var(--color-primary);
    font-size: var(--text-sm);
    overflow: hidden;
    flex-shrink: 0;
}

.avatar--sm { width: 32px; height: 32px; font-size: var(--text-xs); }
.avatar--lg { width: 56px; height: 56px; font-size: var(--text-lg); }
.avatar--xl { width: 80px; height: 80px; font-size: var(--text-2xl); }

.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ── Progress Bar ── */
.progress {
    width: 100%;
    height: 6px;
    background: var(--color-border-light);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress__bar {
    height: 100%;
    border-radius: var(--radius-full);
    background: var(--color-accent);
    transition: width var(--duration-slow) var(--ease-default);
}

.progress__bar--warm { background: var(--color-warm); }
.progress__bar--primary { background: var(--color-primary); }

/* ── Divider ── */
.divider {
    border: none;
    height: 1px;
    background: var(--color-border-light);
    margin: var(--space-6) 0;
}

/* ── Grid ── */
.grid {
    display: grid;
    gap: var(--space-6);
}

.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

/* ── Flex Utilities ── */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* ── Section ── */
.section {
    padding: var(--space-20) 0;
}

.section--alt {
    background: var(--color-surface);
}

.section__header {
    text-align: center;
    max-width: 640px;
    margin: 0 auto var(--space-12);
}

.section__eyebrow {
    font-size: var(--text-sm);
    font-weight: var(--weight-semibold);
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-3);
}

.section__title {
    font-size: var(--text-3xl);
    margin-bottom: var(--space-4);
}

.section__desc {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

/* ── Scroll Animation ── */
.reveal {
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.4s var(--ease-default),
                transform 0.4s var(--ease-default);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
}

/* ── Loading Skeleton ── */
.skeleton {
    background: linear-gradient(90deg, var(--color-border-light) 25%, var(--color-warm-lighter) 50%, var(--color-border-light) 75%);
    background-size: 200% 100%;
    animation: skeleton-pulse 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

@keyframes skeleton-pulse {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ── Toast ── */
.toast-container {
    position: fixed;
    top: var(--space-6);
    right: var(--space-6);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.toast {
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    box-shadow: var(--shadow-xl);
    border-left: 4px solid var(--color-accent);
    min-width: 300px;
    animation: toast-in var(--duration-normal) var(--ease-default);
}

.toast--error { border-left-color: var(--color-error); }
.toast--success { border-left-color: var(--color-success); }

.toast__title {
    font-weight: var(--weight-semibold);
    font-size: var(--text-sm);
    margin-bottom: var(--space-1);
}

.toast__message {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

@keyframes toast-in {
    from { opacity: 0; transform: translateX(100%); }
    to { opacity: 1; transform: translateX(0); }
}

/* ── Modal ── */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(26, 22, 18, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-normal) var(--ease-default);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    max-width: 520px;
    width: 90%;
    max-height: 85vh;
    overflow-y: auto;
    transform: scale(0.95) translateY(10px);
    transition: transform var(--duration-normal) var(--ease-default);
}

.modal-overlay.active .modal {
    transform: scale(1) translateY(0);
}

.modal__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-6);
}

/* ── Responsive ── */
@media (max-width: 1024px) {
    .grid--4 { grid-template-columns: repeat(2, 1fr); }
    .grid--3 { grid-template-columns: repeat(2, 1fr); }
    h1 { font-size: var(--text-3xl); }
    h2 { font-size: var(--text-2xl); }
}

@media (max-width: 768px) {
    :root {
        --space-6: 1.25rem;
    }
    .container { padding: 0 var(--space-4); }
    .grid--4, .grid--3, .grid--2 { grid-template-columns: 1fr; }
    .section { padding: var(--space-12) 0; }
    h1 { font-size: var(--text-2xl); }
    h2 { font-size: var(--text-xl); }

    .hide-mobile { display: none !important; }
}

@media (max-width: 480px) {
    .btn--lg {
        padding: var(--space-3) var(--space-6);
        font-size: var(--text-sm);
    }
}

/* ── Route transition loading bar (G5) ── */
#route-loader {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;
    height: 3px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}
#route-loader.active {
    opacity: 1;
}
.route-loader__bar {
    height: 100%;
    width: 0;
    background: var(--color-accent);
}
#route-loader.active .route-loader__bar {
    animation: route-load 0.5s ease-out forwards;
}
@keyframes route-load {
    0%   { width: 0; }
    50%  { width: 60%; }
    100% { width: 100%; }
}