/* ==================== ROOT VARIABLES ==================== */
:root {
    /* Colors - Light Mode */
    --primary-hue: 250;
    --primary-color: hsl(var(--primary-hue), 85%, 60%);
    --primary-dark: hsl(var(--primary-hue), 85%, 50%);
    --primary-light: hsl(var(--primary-hue), 85%, 70%);
    
    --secondary-hue: 320;
    --secondary-color: hsl(var(--secondary-hue), 75%, 55%);
    
    --accent-hue: 180;
    --accent-color: hsl(var(--accent-hue), 70%, 50%);
    
    --text-color: hsl(0, 0%, 15%);
    --text-light: hsl(0, 0%, 40%);
    --heading-color: hsl(0, 0%, 10%);
    
    --bg-color: hsl(0, 0%, 98%);
    --bg-secondary: hsl(0, 0%, 95%);
    --card-bg: hsl(0, 0%, 100%);
    
    --border-color: hsl(0, 0%, 90%);
    --shadow-sm: 0 2px 8px hsla(0, 0%, 0%, 0.08);
    --shadow-md: 0 4px 16px hsla(0, 0%, 0%, 0.1);
    --shadow-lg: 0 8px 32px hsla(0, 0%, 0%, 0.12);
    
    /* Typography */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    --font-tiny: 0.75rem;
    --font-small: 0.875rem;
    --font-normal: 1rem;
    --font-medium: 1.125rem;
    --font-large: 1.25rem;
    --font-h4: 1.5rem;
    --font-h3: 1.875rem;
    --font-h2: 2.25rem;
    --font-h1: 3rem;
    
    --font-light: 300;
    --font-regular: 400;
    --font-medium-weight: 500;
    --font-semibold: 600;
    --font-bold: 700;
    --font-extrabold: 800;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Layout */
    --container-width: 1200px;
    --header-height: 80px;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --text-color: hsl(0, 0%, 90%);
    --text-light: hsl(0, 0%, 70%);
    --heading-color: hsl(0, 0%, 98%);
    
    --bg-color: hsl(220, 15%, 10%);
    --bg-secondary: hsl(220, 15%, 14%);
    --card-bg: hsl(220, 15%, 16%);
    
    --border-color: hsl(220, 15%, 25%);
    --shadow-sm: 0 2px 8px hsla(0, 0%, 0%, 0.3);
    --shadow-md: 0 4px 16px hsla(0, 0%, 0%, 0.4);
    --shadow-lg: 0 8px 32px hsla(0, 0%, 0%, 0.5);
}

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

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

body {
    font-family: var(--font-body);
    font-size: var(--font-normal);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.7;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--heading-color);
    font-weight: var(--font-bold);
    line-height: 1.2;
}

h1 { font-size: var(--font-h1); }
h2 { font-size: var(--font-h2); }
h3 { font-size: var(--font-h3); }
h4 { font-size: var(--font-h4); }

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

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

button {
    font-family: inherit;
    border: none;
    cursor: pointer;
    background: none;
    transition: all var(--transition-fast);
}

input, textarea {
    font-family: inherit;
    border: none;
    outline: none;
}

ul {
    list-style: none;
}

/* ==================== UTILITIES ==================== */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-3xl) 0;
}

.section-alt {
    background-color: var(--bg-secondary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border-radius: var(--border-radius);
    font-weight: var(--font-semibold);
    font-size: var(--font-normal);
    transition: all var(--transition-normal);
    cursor: pointer;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 16px hsla(var(--primary-hue), 85%, 60%, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px hsla(var(--primary-hue), 85%, 60%, 0.4);
}

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

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* Section Headers */
.section__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.section__title {
    font-size: var(--font-h2);
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.section__title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.section__link {
    color: var(--primary-color);
    font-weight: var(--font-semibold);
    display: flex;
    align-items: center;
    gap: 0.25rem;
    transition: gap var(--transition-fast);
}

.section__link:hover {
    gap: 0.5rem;
}

/* ==================== HEADER & NAVIGATION ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--card-bg);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    background: hsla(0, 0%, 100%, 0.9);
}

[data-theme="dark"] .header.scrolled {
    background: hsla(220, 15%, 16%, 0.9);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
}

.nav__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-large);
    font-weight: var(--font-bold);
    font-family: var(--font-heading);
    color: var(--heading-color);
}

.nav__logo img {
    border-radius: 8px;
}

.nav__menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.nav__list {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav__link {
    font-weight: var(--font-medium-weight);
    color: var(--text-color);
    padding: 0.5rem 0;
    position: relative;
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width var(--transition-fast);
}

.nav__link:hover::after,
.nav__link.active::after {
    width: 100%;
}

.nav__link.active {
    color: var(--primary-color);
}

/* Dropdown */
.dropdown {
    position: relative;
}

.dropdown__menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--card-bg);
    box-shadow: var(--shadow-md);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm);
    min-width: 180px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-normal);
}

.dropdown:hover .dropdown__menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown__menu li {
    margin: 0;
}

.dropdown__menu a {
    display: block;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    transition: background var(--transition-fast);
}

.dropdown__menu a:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

/* Nav Actions */
.nav__actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.search-toggle,
.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    background: var(--bg-secondary);
    transition: all var(--transition-fast);
}

.search-toggle:hover,
.theme-toggle:hover {
    background: var(--primary-color);
    color: white;
    transform: scale(1.1);
}

.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: none;
}

/* Mobile Toggle */
.nav__toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 30px;
    height: 30px;
}

.nav__toggle span {
    width: 100%;
    height: 3px;
    background: var(--text-color);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* Search Bar */
.search-bar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: var(--card-bg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-md) 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-20px);
    transition: all var(--transition-normal);
    z-index: 999;
}

.search-bar.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.search-bar .container {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

#search-input {
    flex: 1;
    padding: 0.875rem 1.25rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    color: var(--text-color);
    font-size: var(--font-medium);
}

#search-input::placeholder {
    color: var(--text-light);
}

.search-close {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    background: var(--bg-secondary);
}

.search-close:hover {
    background: var(--primary-color);
    color: white;
}

/* ==================== HERO SECTION ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    margin-top: var(--header-height);
}

.hero__background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, 
        hsla(var(--primary-hue), 85%, 60%, 0.1),
        hsla(var(--secondary-hue), 75%, 55%, 0.1),
        hsla(var(--accent-hue), 70%, 50%, 0.1)
    );
    z-index: -1;
}

.hero__background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 30%, hsla(var(--primary-hue), 85%, 60%, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, hsla(var(--secondary-hue), 75%, 55%, 0.2) 0%, transparent 50%);
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, -30px) scale(1.1); }
}

.hero__content {
    text-align: center;
    max-width: 800px;
    padding: var(--spacing-xl) 0;
}

.hero__title {
    font-size: clamp(2.5rem, 8vw, 4rem);
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease;
}

.hero__description {
    font-size: var(--font-medium);
    color: var(--text-light);
    margin-bottom: var(--spacing-xl);
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero__cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero__scroll {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-light);
    font-size: var(--font-small);
    animation: bounce 2s ease infinite;
}

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

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

/* ==================== RESPONSIVE ==================== */
@media (max-width: 968px) {
    :root {
        --font-h1: 2.5rem;
        --font-h2: 2rem;
        --font-h3: 1.5rem;
        --spacing-3xl: 4rem;
    }
    
    .nav__menu {
        position: fixed;
        top: var(--header-height);
        left: -100%;
        width: 100%;
        height: calc(100vh - var(--header-height));
        background: var(--card-bg);
        flex-direction: column;
        padding: var(--spacing-xl);
        gap: var(--spacing-md);
        transition: left var(--transition-normal);
        overflow-y: auto;
    }
    
    .nav__menu.active {
        left: 0;
    }
    
    .nav__list {
        flex-direction: column;
        width: 100%;
        gap: 0;
    }
    
    .nav__item {
        width: 100%;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav__link {
        display: block;
        padding: var(--spacing-sm) 0;
    }
    
    .dropdown__menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background: var(--bg-secondary);
        margin-top: var(--spacing-xs);
    }
    
    .nav__toggle {
        display: flex;
    }
    
    .hero__cta {
        flex-direction: column;
    }
}

@media (max-width: 576px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
}