/* CSS Design System for Skill Up Mission */
:root {
    --primary: #1A5F7A;
    --primary-dark: #12485d;
    --secondary: #FF8C32;
    --secondary-dark: #e67616;
    --accent: #00ADB5;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --white: #ffffff;
    --shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 20px 40px -15px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4, .font-heading {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Typography Helper Classes */
.text-center { text-align: center; }
.text-primary { color: var(--primary); }
.text-secondary { color: var(--secondary); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
    text-align: center;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background-color: var(--secondary);
    color: var(--white);
}

.btn-secondary:hover {
    background-color: var(--secondary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

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

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

/* Navigation */
header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
}

.logo span {
    color: var(--secondary);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-links a:hover {
    color: var(--secondary);
}

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Sections */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 50px auto;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

.section-header p {
    color: var(--text-muted);
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    background: linear-gradient(135deg, rgba(26, 95, 122, 0.05) 0%, rgba(255, 140, 50, 0.05) 100%);
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 600px;
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.hero-image {
    position: absolute;
    right: -10%;
    top: 50%;
    transform: translateY(-40%);
    width: 60%;
    z-index: -1;
}

/* Course Cards */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.course-card {
    background: var(--surface);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.course-img {
    height: 200px;
    background: #e2e8f0;
    position: relative;
}

.course-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--secondary);
    color: white;
    padding: 5px 15px;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
}

.course-info {
    padding: 1.5rem;
}

.course-info h3 {
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}

.course-info p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

/* Responsive */
@media (max-width: 992px) {
    .hero h1 { font-size: 3rem; }
    .hero-image { display: none; }
    .hero-content { max-width: 100%; text-align: center; }
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .mobile-menu-btn { display: block; }
}