/* ========================================
   BTS SIO 2025-2027 - Global Stylesheet
   Design System: Off-white, Grass Green, Bright Red
   ======================================== */

/* ========== ROOT VARIABLES ========== */
:root {
    --bg-primary: #FAF9F6;
    --color-primary: #4CAF50;
    --color-scondaire: #7AAF4C;
    --color-accent: #D32F2F;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-border: #E0E0E0;
    --font-main: Arial, Helvetica, sans-serif;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);
}

/* ========== GLOBAL RESET ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========== TYPOGRAPHY ========== */
h1, h2, h3, h4, h5, h6 {
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
    border-bottom: 3px solid var(--color-primary);
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 2rem;
    margin-top: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
}

a {
    color: var(--color-scondaire);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    text-decoration: underline;
}

/* ========== IMPORTANT KEYWORDS (RED) ========== */
.important,
.exam,
.project,
.coefficient,
.urgent {
    color: var(--color-accent);
    font-weight: bold;
}

/* ========== HEADER ========== */
header {
    background: linear-gradient(135deg, var(--color-primary), #66BB6A);
    color: white;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-md);
    top: 0;
    z-index: 1000;
}

header h1 {
    color: white;
    border: none;
    margin: 0;
    font-size: 1.8rem;
}

header .subtitle {
    font-size: 0.9rem;
    opacity: 0.9;
    margin-top: 0.3rem;
}

/* ========== NAVIGATION BAR ========== */
nav {
    background-color: #388E3C;
    box-shadow: var(--shadow-sm);
    top: 0;
    z-index: 999;
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    padding: 0;
    margin: 0;
}

nav ul li {
    margin: 0;
}

nav ul li a {
    display: block;
    padding: 1rem 1.5rem;
    color: white;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

nav ul li a:hover,
nav ul li a.active {
    background-color: var(--color-scondaire);
    text-decoration: none;
}

/* ========== MAIN CONTENT ========== */
main {
    flex: 1;
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
    width: 100%;
}

/* ========== DASHBOARD GRID (Home Page) ========== */
.dashboard {
    margin-top: 2rem;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.subject-card {
    background: white;
    border: 2px solid var(--color-primary);
    border-radius: 8px;
    padding: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    text-align: center;
}

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.subject-card h3 {
    color: var(--color-primary);
    font-size: 1.4rem;
    margin-bottom: 1rem;
}

.subject-card .teacher {
    font-size: 1rem;
    color: var(--color-text-light);
    margin-bottom: 1rem;
}

.subject-card .info {
    font-size: 0.9rem;
    color: var(--color-text);
}

.subject-card .btn {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.6rem 1.5rem;
    background-color: var(--color-primary);
    color: white;
    border-radius: 5px;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

.subject-card .btn:hover {
    background-color: #45a049;
    text-decoration: none;
}

/* ========== SUBJECT PAGE LAYOUT ========== */
.subject-header {
    background: linear-gradient(135deg, var(--color-primary), #66BB6A);
    color: white;
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.subject-header h1 {
    color: white;
    border: none;
}

.subject-header .teacher-name {
    font-size: 1.2rem;
    opacity: 0.95;
    margin-top: 0.5rem;
}

.subject-header .subject-meta {
    display: flex;
    gap: 2rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.subject-header .meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.content-section {
    background: white;
    border: 1px solid var(--color-border);
    border-left: 4px solid var(--color-primary);
    border-radius: 8px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.content-section h2 {
    margin-top: 0;
}

.content-section ul,
.content-section ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.content-section li {
    margin-bottom: 0.5rem;
}

/* ========== RESOURCES SECTION ========== */
.resources-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.resource-item {
    background: var(--bg-primary);
    border: 1px solid var(--color-border);
    border-radius: 5px;
    padding: 1rem;
    transition: border-color 0.3s ease;
}

.resource-item:hover {
    border-color: var(--color-primary);
}

.resource-item h4 {
    color: var(--color-primary);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.resource-item p {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 0.5rem;
}

.resource-item a {
    font-size: 0.9rem;
    font-weight: 500;
}

/* ========== BADGES & TAGS ========== */
.badge {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

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

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

.badge-info {
    background-color: #2196F3;
    color: white;
}

/* ========== FOOTER ========== */
footer {
    background-color: #2E7D32;
    color: white;
    text-align: center;
    padding: 2rem;
    margin-top: auto;
}

footer p {
    margin: 0.5rem 0;
}

footer a {
    color: #A5D6A7;
    font-weight: 500;
}

footer a:hover {
    color: white;
}

/* ========== RESPONSIVE DESIGN ========== */
@media (max-width: 768px) {
    header {
        padding: 1rem;
    }

    header h1 {
        font-size: 1.4rem;
    }

    nav ul {
        flex-direction: column;
    }

    nav ul li a {
        padding: 0.8rem 1rem;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    main {
        padding: 0 1rem;
        margin: 1rem auto;
    }

    .subjects-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .subject-header .subject-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
}

/* ========== UTILITY CLASSES ========== */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }

.highlight {
    background-color: #FFF9C4;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
}