/* ============================================
   CESET - Modern Educational Website Styles
   ============================================ */

/* === CSS Variables (Design System) === */
:root {
    --primary-blue: #1e40af;
    --primary-orange: #f97316;
    --dark-blue: #1e3a8a;
    --light-blue: #3b82f6;
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --text-light: #9ca3af;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-gray: #f3f4f6;
    --border-gray: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --header-height: 80px;
}

/* === Reset & Base Styles === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

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

ul {
    list-style: none;
}

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

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-gray);
    line-height: 1.75;
}

/* === Header Styles === */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: var(--transition);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Logo Styles */
.logo a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-blue);
}

.logo-img {
    width: 50px;
    height: 50px;
    object-fit: contain;
}

.logo-text {
    font-size: 1.75rem;
    letter-spacing: -0.5px;
}

/* Desktop Navigation */
.nav-desktop {
    display: flex;
}

.nav-menu {
    display: flex;
    gap: 2.5rem;
    align-items: center;
}

.nav-link {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    padding: 0.5rem 0;
    position: relative;
    transition: var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-orange);
    transition: width 0.3s ease;
}

.nav-link:hover {
    color: var(--primary-orange);
}

.nav-link:hover::after {
    width: 100%;
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger-line {
    width: 28px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

.hamburger.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.hamburger.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.hamburger.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(8px, -8px);
}

/* Mobile Navigation */
.nav-mobile {
    display: none;
    position: fixed;
    top: var(--header-height);
    right: -100%;
    width: 300px;
    height: calc(100vh - var(--header-height));
    background: var(--bg-white);
    box-shadow: var(--shadow-xl);
    transition: right 0.3s ease;
    z-index: 999;
}

.nav-mobile.active {
    right: 0;
}

.nav-menu-mobile {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.nav-link-mobile {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-dark);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-link-mobile:hover {
    background: var(--bg-gray);
    color: var(--primary-orange);
}

/* === Main Content Spacing === */
.main-content {
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
}

/* === Hero Section === */
.hero {
    position: relative;
    height: 600px;
    background: linear-gradient(135deg, var(--dark-blue) 0%, var(--primary-blue) 100%);
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/hero-main.jpg');
    background-size: cover;
    background-position: center;
    opacity: 0.15;
    z-index: 0;
}

.hero-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    position: relative;
    z-index: 1;
}

.hero-content {
    max-width: 700px;
    color: var(--bg-white);
}

.hero-title {
    font-size: 3.5rem;
    color: var(--bg-white);
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* === Buttons === */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    transition: var(--transition);
    text-align: center;
}

.btn-primary {
    background: var(--primary-orange);
    color: var(--bg-white);
}

.btn-primary:hover {
    background: #ea580c;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-white);
    color: var(--primary-blue);
    border: 2px solid var(--bg-white);
}

.btn-secondary:hover {
    background: transparent;
    color: var(--bg-white);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

.btn-outline:hover {
    background: var(--primary-blue);
    color: var(--bg-white);
}

/* === Container & Section Styles === */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title h2 {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.section-title p {
    font-size: 1.125rem;
    color: var(--text-gray);
    max-width: 700px;
    margin: 0 auto;
}

/* === Grid Layouts === */
.grid {
    display: grid;
    gap: 2rem;
}

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

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

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

/* === Card Styles === */
.card {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-gray);
}

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

.card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.card-title {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.card-text {
    color: var(--text-gray);
    margin-bottom: 1rem;
}

.card-link {
    color: var(--primary-orange);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.card-link:hover {
    color: var(--primary-blue);
}

/* === Feature Box === */
.feature-box {
    text-align: center;
    padding: 2rem;
    background: var(--bg-light);
    border-radius: 12px;
    transition: var(--transition);
}

.feature-box:hover {
    background: var(--bg-white);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: var(--primary-orange);
    color: var(--bg-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin: 0 auto 1.5rem;
}

.feature-title {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.feature-text {
    color: var(--text-gray);
}

/* === Stats Section === */
.stats {
    background: var(--primary-blue);
    color: var(--bg-white);
    padding: 4rem 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 3rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-orange);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.9);
}

/* === Footer Styles === */
.site-footer {
    background: var(--text-dark);
    color: var(--bg-white);
    padding: 4rem 0 2rem;
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-top {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h3 {
    color: var(--bg-white);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.footer-col h4 {
    color: var(--bg-white);
    font-size: 1.125rem;
    margin-bottom: 1rem;
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.footer-tagline {
    margin-top: 1rem;
    font-style: italic;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-orange);
    padding-left: 5px;
}

.footer-contact {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    color: rgba(255, 255, 255, 0.7);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* === Form Styles === */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-gray);
    border-radius: 8px;
    transition: var(--transition);
    font-family: inherit;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

/* === Responsive Design === */
@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-top {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 70px;
    }
    
    /* Typography scaling */
    h1 { font-size: 2.25rem; }
    h2 { font-size: 1.875rem; }
    h3 { font-size: 1.5rem; }
    
    /* Header mobile */
    .nav-desktop {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .nav-mobile {
        display: block;
    }
    
    /* Hero mobile */
    .hero {
        height: 500px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    /* Grid mobile */
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-top {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    /* Section padding */
    .section {
        padding: 3rem 0;
    }
    
    .container {
        padding: 0 1.25rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
    
    .logo-img {
        width: 40px;
        height: 40px;
    }
}

/* === Animations === */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* === Utility Classes === */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.bg-light { background-color: var(--bg-light); }
.bg-gray { background-color: var(--bg-gray); }

.text-primary { color: var(--primary-blue); }
.text-orange { color: var(--primary-orange); }
.text-gray { color: var(--text-gray); }