/* Master CSS — Global Design System
   IQMS — Interactive Quiz Management System
   Theme: Premium Light (deep indigo #4F46E5 + teal #0D9488, soft light background)
   Page-specific styles should go in separate files (e.g., quiz-editor.css). */

/* ============================================================
   CSS Variables / Design Tokens
   ============================================================ */
:root {
    /* Background Colors */
    --primary-bg: #F8FAFC;
    --secondary-bg: #F1F5F9;
    --surface-bg: #FFFFFF;
    --elevated-bg: #FFFFFF;

    /* Accent Colors */
    --primary-accent: #4F46E5;
    --secondary-accent: #0D9488;
    --primary-accent-hover: #4338CA;
    --primary-accent-soft: #EEF2FF;
    --secondary-accent-soft: #F0FDFA;

    /* Text Colors */
    --primary-text: #1E293B;
    --secondary-text: #475569;
    --muted-text: #64748B;

    /* Status Colors */
    --success-color: #16A34A;
    --success-soft: #F0FDF4;
    --error-color: #DC2626;
    --error-soft: #FEF2F2;
    --warning-color: #D97706;
    --warning-soft: #FFFBEB;
    --info-color: #4F46E5;

    /* Misc */
    --white: #FFFFFF;
    --black: #0F172A;
    --border-color: #E2E8F0;
    --border-radius: 16px;
    --radius-sm: 10px;
    --radius-lg: 22px;
    --transition-speed: 0.25s;

    /* Shadows */
    --shadow-card: 0 4px 20px rgba(15, 23, 42, 0.06);
    --shadow-card-hover: 0 14px 34px rgba(79, 70, 229, 0.14);
    --shadow-pop: 0 20px 50px rgba(15, 23, 42, 0.18);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Poppins', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'Fira Code', 'Consolas', monospace;
}

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

/* ============================================================
   Base Styles
   ============================================================ */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    background-color: var(--primary-bg);
    font-family: var(--font-primary);
    color: var(--primary-text);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-size: 1rem;
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ============================================================
   Typography
   ============================================================ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    line-height: 1.3;
    font-weight: 600;
    color: var(--primary-text);
    letter-spacing: -0.02em;
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }

p { margin-bottom: 1rem; }

a {
    color: var(--primary-accent);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}
a:hover {
    color: var(--primary-accent-hover);
}

.text-muted { color: var(--muted-text); }
.text-secondary { color: var(--secondary-text); }
.text-brand { color: var(--primary-accent); }
.text-teal { color: var(--secondary-accent); }
.text-success { color: var(--success-color); }
.text-error { color: var(--error-color); }
.text-warning { color: var(--warning-color); }
.text-center { text-align: center; }

.gradient-text {
    background: linear-gradient(120deg, #4F46E5 0%, #0D9488 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

/* ============================================================
   Layout Utilities
   ============================================================ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    flex: 1;
}

.hidden { display: none !important; }

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* ============================================================
   Buttons
   ============================================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.7rem 1.4rem;
    font-size: 1rem;
    font-weight: 600;
    font-family: var(--font-primary);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--transition-speed) ease;
    text-decoration: none;
    line-height: 1.4;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.18);
}
.btn:active {
    transform: translateY(0);
}
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-primary {
    background-color: var(--primary-accent);
    color: var(--white);
}
.btn-primary:hover {
    background-color: var(--primary-accent-hover);
    color: var(--white);
}

.btn-secondary {
    background-color: var(--surface-bg);
    color: var(--primary-text);
    border: 1.5px solid var(--border-color);
}
.btn-secondary:hover {
    border-color: var(--primary-accent);
    color: var(--primary-accent);
    background-color: var(--primary-accent-soft);
}

.btn-outline {
    background: transparent;
    color: var(--primary-accent);
    border: 1.5px solid var(--primary-accent);
}
.btn-outline:hover {
    background: var(--primary-accent);
    color: var(--white);
}

.btn-teal {
    background-color: var(--secondary-accent);
    color: var(--white);
}
.btn-teal:hover {
    background-color: #0F766E;
    color: var(--white);
}

.btn-danger {
    background-color: var(--error-color);
    color: var(--white);
}
.btn-danger:hover {
    background-color: #B91C1C;
    color: var(--white);
}

.btn-ghost {
    background: transparent;
    color: var(--secondary-text);
    border: 1px solid transparent;
}
.btn-ghost:hover {
    background: var(--secondary-bg);
    color: var(--primary-text);
    box-shadow: none;
}

.btn-sm { padding: 0.45rem 0.9rem; font-size: 0.875rem; border-radius: 8px; }
.btn-lg { padding: 0.9rem 2rem; font-size: 1.1rem; border-radius: var(--radius-sm); }
.btn-block { width: 100%; }
.btn-icon { padding: 0.5rem; border-radius: 10px; }
.btn-icon.btn-sm { padding: 0.35rem; border-radius: 8px; }

/* ============================================================
   Forms
   ============================================================ */
label {
    display: block;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--primary-text);
    margin-bottom: 0.4rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="search"],
input[type="url"],
input[type="tel"],
textarea,
select {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    font-family: var(--font-primary);
    color: var(--primary-text);
    background-color: var(--surface-bg);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: border-color var(--transition-speed), box-shadow var(--transition-speed);
    outline: none;
}

input:focus,
textarea:focus,
select:focus {
    border-color: var(--primary-accent);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.12);
}

input::placeholder,
textarea::placeholder {
    color: #94A3B8;
}

.form-group { margin-bottom: 1.25rem; }

.form-hint {
    font-size: 0.85rem;
    color: var(--muted-text);
    margin-top: 0.35rem;
}

.form-error {
    font-size: 0.85rem;
    color: var(--error-color);
    margin-top: 0.35rem;
}

/* Custom checkbox / radio (accent color) */
input[type="checkbox"],
input[type="radio"] {
    accent-color: var(--primary-accent);
    width: 1.1rem;
    height: 1.1rem;
    cursor: pointer;
}

/* ============================================================
   Cards
   ============================================================ */
.card {
    background: var(--surface-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-card);
    padding: 1.5rem;
}

.card-hover {
    transition: transform var(--transition-speed), box-shadow var(--transition-speed), border-color var(--transition-speed);
}
.card-hover:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
    border-color: #C7D2FE;
}

.card-title {
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

/* ============================================================
   Badges
   ============================================================ */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 600;
    line-height: 1.6;
    white-space: nowrap;
}

.badge-indigo { background: var(--primary-accent-soft); color: var(--primary-accent); }
.badge-teal { background: var(--secondary-accent-soft); color: var(--secondary-accent); }
.badge-green { background: var(--success-soft); color: var(--success-color); }
.badge-red { background: var(--error-soft); color: var(--error-color); }
.badge-amber { background: var(--warning-soft); color: var(--warning-color); }
.badge-slate { background: var(--secondary-bg); color: var(--secondary-text); }

/* ============================================================
   Tables
   ============================================================ */
.table-wrap {
    background: var(--surface-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.data-table th {
    text-align: left;
    padding: 0.85rem 1.25rem;
    background: var(--secondary-bg);
    color: var(--secondary-text);
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

.data-table td {
    padding: 0.9rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--primary-text);
    vertical-align: middle;
}

.data-table tbody tr:last-child td { border-bottom: none; }
.data-table tbody tr { transition: background-color var(--transition-speed); }
.data-table tbody tr:hover { background: #F8FAFC; }

/* ============================================================
   Header
   ============================================================ */
.site-header {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
    gap: 1rem;
}

.header-brand {
    display: flex;
    align-items: center;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    color: var(--primary-text);
    font-weight: 700;
    font-size: 1.35rem;
    font-family: var(--font-heading);
    letter-spacing: -0.02em;
    text-decoration: none;
}
.brand-link:hover { color: var(--primary-text); }

.brand-logo {
    height: 40px;
    width: auto;
}

.brand-text {
    background: linear-gradient(120deg, #4F46E5 0%, #0D9488 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 0.35rem;
    align-items: center;
}

.nav-link {
    padding: 0.5rem 0.9rem;
    color: var(--secondary-text);
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-speed), background-color var(--transition-speed);
}
.nav-link:hover,
.nav-link.active {
    color: var(--primary-accent);
    background-color: var(--primary-accent-soft);
}

/* User chip */
.user-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    padding: 0.35rem 0.9rem 0.35rem 0.4rem;
    background: var(--secondary-bg);
    border-radius: 9999px;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--primary-text);
}
.avatar {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: 9999px;
    background: linear-gradient(135deg, #4F46E5, #0D9488);
    color: #fff;
    font-weight: 700;
    font-size: 0.8rem;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    border-radius: 8px;
}
.mobile-menu-toggle:hover { background: var(--secondary-bg); }

.menu-bar {
    display: block;
    width: 24px;
    height: 2.5px;
    background-color: var(--primary-text);
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
}

.mobile-menu-toggle.active .menu-bar:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.mobile-menu-toggle.active .menu-bar:nth-child(2) { opacity: 0; }
.mobile-menu-toggle.active .menu-bar:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* Mobile Navigation */
.mobile-nav {
    display: none;
    background: var(--surface-bg);
    border-top: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem 1.25rem;
}

.mobile-nav.open { display: block; }

.mobile-nav-list {
    list-style: none;
}

.mobile-nav-link {
    display: block;
    padding: 0.75rem 0;
    color: var(--secondary-text);
    border-bottom: 1px solid var(--border-color);
    font-weight: 500;
    font-size: 1rem;
}
.mobile-nav-link:hover,
.mobile-nav-link.active {
    color: var(--primary-accent);
}

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
    background: var(--secondary-bg);
    border-top: 1px solid var(--border-color);
    padding: 1.75rem 1.5rem;
    text-align: center;
    margin-top: auto;
}

.copyright {
    color: var(--muted-text);
    font-size: 0.9rem;
}

.footer-tagline {
    color: var(--secondary-text);
    font-size: 0.95rem;
    font-weight: 500;
    margin-bottom: 0.35rem;
}

/* ============================================================
   Notification Popup (Toast)
   ============================================================ */
.notification-popup {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background-color: var(--surface-bg);
    color: var(--primary-text);
    border-radius: var(--radius-sm);
    padding: 16px;
    min-width: 300px;
    max-width: 380px;
    box-shadow: var(--shadow-pop);
    border-left: 4px solid var(--primary-accent);
    border: 1px solid var(--border-color);

    /* Hidden by default — animated in by .show class */
    transform: translateX(120%);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.4s ease-in-out, opacity 0.4s ease, visibility 0.4s ease;
}

.notification-popup.show {
    transform: translateX(0);
    opacity: 1;
    visibility: visible;
}

.notification-popup.success { border-left-color: var(--success-color); }
.notification-popup.error { border-left-color: var(--error-color); }
.notification-popup.warning { border-left-color: var(--warning-color); }

.notification-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.notification-icon {
    font-size: 1.3rem;
    flex-shrink: 0;
}

.notification-popup.success .notification-icon { color: var(--success-color); }
.notification-popup.error .notification-icon { color: var(--error-color); }
.notification-popup.warning .notification-icon { color: var(--warning-color); }

.notification-message {
    flex-grow: 1;
    font-size: 0.95rem;
    line-height: 1.5;
    margin: 0;
}

.notification-close {
    background: none;
    border: none;
    color: var(--muted-text);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 0 4px;
    transition: color var(--transition-speed);
    flex-shrink: 0;
}
.notification-close:hover { color: var(--primary-text); }

/* Progress bar (auto-dismiss countdown) */
.notification-progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--secondary-bg);
    border-bottom-left-radius: var(--radius-sm);
    border-bottom-right-radius: var(--radius-sm);
    overflow: hidden;
}

.notification-progress-bar div {
    height: 100%;
    background-color: var(--primary-accent);
    border-bottom-left-radius: var(--radius-sm);
    width: 0%;
}

.notification-popup.success .notification-progress-bar div { background-color: var(--success-color); }
.notification-popup.error .notification-progress-bar div { background-color: var(--error-color); }
.notification-popup.warning .notification-progress-bar div { background-color: var(--warning-color); }

.notification-popup.show .notification-progress-bar div {
    animation: progressBar 6s linear forwards;
}

@keyframes progressBar {
    from { width: 100%; }
    to { width: 0%; }
}

/* ============================================================
   Skeleton Loaders
   ============================================================ */
.skeleton {
    position: relative;
    overflow: hidden;
    background-color: #E2E8F0;
    border-radius: var(--radius-sm);
    min-height: 1em;
}

.skeleton::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.65), transparent);
    animation: shimmer 1.4s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* ============================================================
   Micro-animations & Utility Effects
   ============================================================ */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
    animation: fadeInUp 0.5s ease both;
}

.hover-lift {
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}
.hover-lift:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}

/* Divider */
.divider {
    height: 1px;
    background: var(--border-color);
    border: none;
    margin: 1.25rem 0;
}

/* Progress bar (generic) */
.progress-track {
    width: 100%;
    height: 10px;
    background: var(--secondary-bg);
    border-radius: 9999px;
    overflow: hidden;
}
.progress-fill {
    height: 100%;
    border-radius: 9999px;
    background: linear-gradient(90deg, #4F46E5, #0D9488);
    transition: width 0.5s ease;
}

/* ============================================================
   Responsive Design
   ============================================================ */
@media (max-width: 768px) {
    .header-nav { display: none; }
    .mobile-menu-toggle { display: flex; }
    .header-container { height: 60px; }

    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.4rem; }

    .container { padding: 1.25rem 1rem; }

    .notification-popup {
        top: 12px;
        right: 12px;
        left: 12px;
        min-width: 0;
        max-width: none;
    }
}

/* ============================================================
   Landing Page Helpers
   ============================================================ */
/* Gentle floating animation for hero chips */
.animate-bounce-slow {
    animation: floatY 5s ease-in-out infinite;
}
.animate-bounce-slower {
    animation: floatY 7s ease-in-out infinite 1.2s;
}

@keyframes floatY {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* Scroll-reveal (used by landing.js IntersectionObserver) */
.reveal {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Respect users who prefer reduced motion */
@media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
    .animate-bounce-slow,
    .animate-bounce-slower { animation: none; }
}