@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Outfit:wght@500;700;900&display=swap');

:root {
    /* Color Palette - Premium Data Tech */
    --primary: hsl(210, 100%, 60%);
    --primary-glow: hsla(210, 100%, 60%, 0.3);
    --secondary: hsl(270, 90%, 65%);
    --secondary-glow: hsla(270, 90%, 65%, 0.3);
    --accent: hsl(180, 100%, 50%);
    
    --bg-dark: hsl(222, 47%, 4%);
    --bg-surface: hsla(222, 47%, 10%, 0.8);
    --bg-card: hsla(222, 47%, 15%, 0.4);
    
    --text-main: hsl(210, 20%, 95%);
    --text-muted: hsl(210, 10%, 70%);
    
    --border: hsla(210, 20%, 25%, 0.4);
    --glass-border: hsla(210, 20%, 100%, 0.1);
    
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 24px 48px rgba(0, 0, 0, 0.6);
    
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-norm: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

h1, h2, h3, h4 {
    font-family: 'Outfit', sans-serif;
    line-height: 1.1;
    font-weight: 700;
}

/* Glassmorphism Utilities */
.glass {
    background: var(--bg-surface);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
}

/* Background Gradients */
.bg-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 10% 20%, hsla(210, 100%, 10%, 0.4) 0%, transparent 60%),
                radial-gradient(circle at 90% 80%, hsla(270, 90%, 10%, 0.4) 0%, transparent 60%);
    z-index: -1;
}

/* Header & Nav */
header {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 2rem;
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 900px;
    z-index: 2;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 5.5rem);
    background: linear-gradient(135deg, #fff 0%, var(--primary) 50%, var(--secondary) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 2rem;
    font-weight: 900;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1rem, 3vw, 1.5rem);
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 3rem;
}

/* Navigation */
nav {
    position: sticky;
    top: 1rem;
    width: fit-content;
    margin: 0 auto;
    padding: 0.75rem 1.5rem;
    z-index: 100;
    display: flex;
    gap: 1.5rem;
    margin-bottom: 4rem;
}

nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition-fast);
}

nav a:hover, nav a.active {
    color: var(--primary);
}

/* Main Content */
main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 8rem 0;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

section.visible {
    opacity: 1;
    transform: translateY(0);
}

.section-head {
    margin-bottom: 4rem;
    text-align: center;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    margin-bottom: 1rem;
    color: var(--text-main);
}

.section-image {
    width: 100%;
    max-width: 700px;
    height: 400px;
    background: var(--bg-card);
    border-radius: 2rem;
    margin: 2rem auto;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--glass-border);
    overflow: hidden;
}

.section-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.section-image:hover img {
    transform: scale(1.05);
}

/* Mistake Cards */
.mistakes-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.mistake-card {
    padding: 2rem;
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    transition: var(--transition-norm);
    cursor: default;
}

.mistake-card:hover {
    background: hsla(222, 47%, 20%, 0.6);
    transform: translateX(10px);
    border-color: var(--primary);
}

.mistake-number {
    font-size: 1.5rem;
    font-weight: 900;
    font-family: 'Outfit', sans-serif;
    color: var(--primary);
    min-width: 3rem;
}

.mistake-content h3 {
    margin-bottom: 0.5rem;
    font-size: 1.25rem;
}

.mistake-content p {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Progress Bar */
.progress-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    z-index: 1000;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    width: 0%;
}

/* Scroll Snap (Optional) */
/* Social Share Widget */
.share-widget {
    position: fixed;
    left: 2rem;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    z-index: 1000;
}

.share-btn {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    text-decoration: none;
    background: transparent;
    border: 1px solid var(--glass-border);
    transition: var(--transition-fast);
    cursor: pointer;
}

.share-btn:hover {
    color: #fff;
    background: var(--surface);
    transform: scale(1.1);
    border-color: var(--primary);
}

.share-btn.linkedin:hover { color: #0077b5; }
.share-btn.twitter:hover { color: #1da1f2; }
.share-btn.reddit:hover { color: #ff4500; }
.share-btn.copy:hover { color: var(--accent); }

@media (max-width: 1200px) {
    .share-widget {
        left: auto;
        right: 1rem;
        top: auto;
        bottom: 2rem;
        flex-direction: row;
        transform: none;
        border-radius: 2rem;
    }
}

@media (max-width: 768px) {
    .share-widget {
        width: calc(100% - 2rem);
        left: 1rem;
        right: 1rem;
        bottom: 1rem;
        justify-content: center;
        padding: 0.5rem;
    }
}