/**
 * BTC University - Main Stylesheet
 * Core styles for the BTCU Learning Management System
 * 
 * Imports the design system variables and provides base styles,
 * utility classes, and component foundations.
 */

@import url('./variables.css');

/* Google Fonts Import */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Playfair+Display:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ============================================
   CSS RESET & BASE STYLES
============================================ */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Main content wrapper - accounts for fixed header */
main {
    padding-top: var(--header-height);
}

/* ============================================
   TYPOGRAPHY BASE STYLES
============================================ */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: var(--font-semibold);
    line-height: var(--leading-tight);
    color: var(--btcu-navy);
    margin-bottom: var(--space-4);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
    margin-bottom: var(--space-4);
    color: var(--btcu-gray-600);
}

a {
    color: var(--btcu-orange);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--btcu-orange-dark);
}

strong, b {
    font-weight: var(--font-semibold);
}

/* Lists */
ul, ol {
    margin-left: var(--space-6);
    margin-bottom: var(--space-4);
}

li {
    margin-bottom: var(--space-2);
}

/* Code */
code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background-color: var(--btcu-gray-100);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-default);
}

pre {
    font-family: var(--font-mono);
    background-color: var(--btcu-navy-dark);
    color: var(--btcu-gold-light);
    padding: var(--space-4);
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin-bottom: var(--space-4);
}

pre code {
    background: none;
    padding: 0;
}

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

.container {
    width: 100%;
    max-width: var(--container-full);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container-sm { max-width: var(--container-5xl); }
.container-md { max-width: var(--container-6xl); }
.container-lg { max-width: var(--container-7xl); }

/* Flex utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.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); }
.gap-10 { gap: var(--space-10); }
.gap-12 { gap: var(--space-12); }

/* Grid utilities */
.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

@media (max-width: 1024px) {
    .lg\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .lg\:grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
}

@media (max-width: 768px) {
    .md\:grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
    .md\:flex-col { flex-direction: column; }
}

/* Spacing utilities */
.mt-auto { margin-top: auto; }
.mb-auto { margin-bottom: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* ============================================
   SECTION STYLES
============================================ */

.section {
    padding: var(--space-20) 0;
}

.section-sm {
    padding: var(--space-12) 0;
}

.section-lg {
    padding: var(--space-24) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-12);
}

.section-header h2 {
    margin-bottom: var(--space-4);
}

.section-header p {
    max-width: 40rem;
    margin: 0 auto;
    font-size: var(--text-lg);
}

/* ============================================
   BUTTON STYLES
============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-family: var(--font-body);
    font-size: var(--text-base);
    font-weight: var(--font-medium);
    text-decoration: none;
    border: var(--border-width-default) solid transparent;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-default);
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Primary Button - Orange */
.btn-primary {
    background-color: var(--btcu-orange);
    color: var(--btcu-white);
    border-color: var(--btcu-orange);
}

.btn-primary:hover {
    background-color: var(--btcu-orange-dark);
    border-color: var(--btcu-orange-dark);
    color: var(--btcu-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Secondary Button - Navy */
.btn-secondary {
    background-color: var(--btcu-navy);
    color: var(--btcu-white);
    border-color: var(--btcu-navy);
}

.btn-secondary:hover {
    background-color: var(--btcu-navy-light);
    border-color: var(--btcu-navy-light);
    color: var(--btcu-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Outline Button - Gold */
.btn-outline {
    background-color: transparent;
    color: var(--btcu-gold-dark);
    border-color: var(--btcu-gold);
}

.btn-outline:hover {
    background-color: var(--btcu-gold);
    color: var(--btcu-navy);
    transform: translateY(-2px);
}

/* Ghost Button */
.btn-ghost {
    background-color: transparent;
    color: var(--btcu-navy);
    border-color: transparent;
}

.btn-ghost:hover {
    background-color: var(--btcu-gray-100);
    color: var(--btcu-navy);
}

/* Button Sizes */
.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
}

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

.btn-xl {
    padding: var(--space-5) var(--space-10);
    font-size: var(--text-xl);
}

/* Icon Button */
.btn-icon {
    padding: var(--space-3);
    width: 2.75rem;
    height: 2.75rem;
}

/* ============================================
   CARD STYLES
============================================ */

.card {
    background-color: var(--btcu-white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all var(--transition-default);
}

.card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-4px);
}

.card-header {
    padding: var(--space-6);
    border-bottom: 1px solid var(--btcu-gray-200);
}

.card-body {
    padding: var(--space-6);
}

.card-footer {
    padding: var(--space-6);
    border-top: 1px solid var(--btcu-gray-200);
    background-color: var(--btcu-gray-100);
}

/* ============================================
   BADGE STYLES
============================================ */

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    border-radius: var(--radius-full);
}

.badge-gold {
    background-color: var(--btcu-gold-light);
    color: var(--btcu-navy);
}

.badge-orange {
    background-color: var(--btcu-orange);
    color: var(--btcu-white);
}

.badge-navy {
    background-color: var(--btcu-navy);
    color: var(--btcu-white);
}

.badge-success {
    background-color: var(--btcu-success-light);
    color: var(--btcu-success);
}

/* ============================================
   FORM STYLES
============================================ */

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

.form-label {
    display: block;
    margin-bottom: var(--space-2);
    font-weight: var(--font-medium);
    color: var(--btcu-navy);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--btcu-navy);
    background-color: var(--btcu-white);
    border: var(--border-width-thin) solid var(--btcu-gray-300);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--btcu-gold);
    box-shadow: 0 0 0 3px rgba(201, 184, 150, 0.2);
}

.form-input::placeholder {
    color: var(--btcu-gray-400);
}

.form-textarea {
    min-height: 8rem;
    resize: vertical;
}

/* ============================================
   NAVIGATION DOTS / PROGRESS
============================================ */

.progress-bar {
    height: 0.5rem;
    background-color: var(--btcu-gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--btcu-orange), var(--btcu-gold));
    border-radius: var(--radius-full);
    transition: width var(--transition-slow);
}

/* ============================================
   ANIMATIONS
============================================ */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

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

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

.animate-fade-in { animation: fadeIn 0.5s ease forwards; }
.animate-fade-in-up { animation: fadeInUp 0.6s ease forwards; }
.animate-slide-in-left { animation: slideInLeft 0.5s ease forwards; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }
.animate-float { animation: float 3s ease-in-out infinite; }

/* Stagger delays for sequential animations */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-400 { animation-delay: 400ms; }
.delay-500 { animation-delay: 500ms; }

/* ============================================
   VISIBILITY & RESPONSIVE UTILITIES
============================================ */

.hidden { display: none !important; }
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@media (max-width: 768px) {
    .md\:hidden { display: none !important; }
    .md\:block { display: block !important; }
    .md\:flex { display: flex !important; }
}

@media (min-width: 769px) {
    .md\:show { display: block !important; }
}

@media (max-width: 1024px) {
    .lg\:hidden { display: none !important; }
}

/* ============================================
   SCROLLBAR STYLING
============================================ */

::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--btcu-gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--btcu-gold);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--btcu-gold-dark);
}

/* Firefox */
html {
    scrollbar-width: thin;
    scrollbar-color: var(--btcu-gold) var(--btcu-gray-100);
}

/* ============================================
   SELECTION STYLING
============================================ */

::selection {
    background-color: var(--btcu-gold);
    color: var(--btcu-navy);
}

::-moz-selection {
    background-color: var(--btcu-gold);
    color: var(--btcu-navy);
}