/* Dark Mode Styles */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f5f7fa;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    --border-color: #e0e0e0;
    --card-bg: #ffffff;
    --card-hover: #f0f0f0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-tertiary: #0f3460;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-tertiary: #808080;
    --border-color: #2a2a4a;
    --card-bg: #16213e;
    --card-hover: #1a1a2e;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.4);
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Navbar */
.navbar {
    background-color: rgba(255, 255, 255, 0.95);
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .navbar {
    background-color: rgba(26, 26, 46, 0.95);
}

/* Cards */
.card, .content-card, .stat-card, .feature-card, .teacher-card, .course-item {
    background-color: var(--card-bg);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 10px 30px var(--shadow-color);
}

.card:hover, .content-card:hover, .feature-card:hover, .course-item:hover {
    background-color: var(--card-hover);
    box-shadow: 0 20px 40px var(--shadow-hover);
}

/* Text Colors */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    transition: color 0.3s ease;
}

p, span, div, a {
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

/* Links */
a {
    color: var(--text-secondary);
}

a:hover {
    color: #667eea;
}

/* Buttons */
.btn, .nav-btn, .hero-btn, .cta-btn, .feature-cta, .action-btn {
    transition: all 0.3s ease;
}

/* Form Elements */
input, textarea, select {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border-color: var(--border-color);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

input:focus, textarea:focus, select:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Tables */
table {
    background-color: var(--card-bg);
}

th, td {
    border-color: var(--border-color);
    color: var(--text-primary);
}

/* Progress Bars */
.progress-bar {
    background-color: var(--border-color);
}

/* Badges */
.badge {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Sections */
.section {
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease;
}

.section:nth-child(even) {
    background-color: var(--bg-secondary);
}

/* Footer */
.footer {
    background-color: #1a1a2e;
    color: white;
}

/* Dark Mode Toggle Button */
.dark-mode-toggle {
    background: none;
    border: 2px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    margin-left: 1rem;
}

.dark-mode-toggle:hover {
    background: #667eea;
    color: white;
}

[data-theme="dark"] .dark-mode-toggle {
    background: #667eea;
    color: white;
}

/* Smooth Transitions */
* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: #764ba2;
}