/* ============================================================
   IMGROUP Ads Manager — Landing Page Styles
   Thiết kế: Premium, dark theme, glassmorphism
   ============================================================ */

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

:root {
    --primary: #1a73e8;
    --primary-dark: #1557b0;
    --primary-light: #4a9af5;
    --accent: #8b5cf6;
    --bg-dark: #0a0e1a;
    --bg-section: #0f1629;
    --surface: #161b2e;
    --surface-light: #1e2642;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --text-dim: #64748b;
    --border: rgba(255,255,255,0.08);
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 20px 60px rgba(0,0,0,0.4);
}

html { scroll-behavior: smooth; }

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

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* === Header === */
.header {
    position: fixed; top: 0; left: 0; right: 0;
    z-index: 100;
    backdrop-filter: blur(20px);
    background: rgba(10,14,26,0.8);
    border-bottom: 1px solid var(--border);
}

.header-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex; align-items: center; gap: 0.6rem;
    font-weight: 700; font-size: 1.15rem; color: white;
}

.logo-icon {
    width: 36px; height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 10px;
    display: flex; align-items: center; justify-content: center;
    color: white;
}

.nav { display: flex; align-items: center; gap: 0.25rem; }

.nav-link {
    padding: 0.5rem 1rem;
    font-size: 0.9rem; font-weight: 500;
    color: var(--text-muted);
    border-radius: 8px;
    transition: all 0.2s;
}
.nav-link:hover { color: white; background: rgba(255,255,255,0.06); }

.nav-admin {
    background: rgba(139,92,246,0.15);
    color: var(--accent);
    border: 1px solid rgba(139,92,246,0.2);
}
.nav-admin:hover {
    background: rgba(139,92,246,0.25);
    color: #a78bfa;
}

/* === Hero === */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    text-align: center;
    padding: 6rem 1.5rem 4rem;
    overflow: hidden;
}

.hero-bg {
    position: absolute; inset: 0;
    pointer-events: none;
}

/* Hiệu ứng orb (gradient circles) */
.hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 8s ease-in-out infinite;
}
.hero-orb-1 {
    width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(26,115,232,0.5), transparent);
    top: 10%; left: 20%;
}
.hero-orb-2 {
    width: 400px; height: 400px;
    background: radial-gradient(circle, rgba(139,92,246,0.4), transparent);
    bottom: 20%; right: 15%;
    animation-delay: -3s;
}
.hero-orb-3 {
    width: 300px; height: 300px;
    background: radial-gradient(circle, rgba(59,130,246,0.3), transparent);
    top: 50%; left: 60%;
    animation-delay: -5s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -20px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

/* Grid pattern overlay */
.hero-grid {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
}

.hero-content {
    position: relative; z-index: 1;
    max-width: 700px;
}

/* Badge */
.hero-badge {
    display: inline-flex; align-items: center; gap: 0.5rem;
    background: rgba(26,115,232,0.12);
    border: 1px solid rgba(26,115,232,0.2);
    border-radius: 999px;
    padding: 0.45rem 1.2rem;
    font-size: 0.85rem; font-weight: 500;
    color: var(--primary-light);
    margin-bottom: 2rem;
    animation: fadeInDown 0.6s ease-out;
}

.badge-dot {
    width: 8px; height: 8px;
    background: #22c55e;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Title */
.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 1.25rem;
    animation: fadeInUp 0.7s ease-out 0.1s both;
}

.gradient-text {
    background: linear-gradient(135deg, #4a9af5, #8b5cf6, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--text-muted);
    max-width: 540px;
    margin: 0 auto 2.5rem;
    line-height: 1.7;
    animation: fadeInUp 0.7s ease-out 0.2s both;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Google Button */
.google-btn {
    display: inline-flex; align-items: center; gap: 0.75rem;
    background: white;
    color: #3c4043;
    padding: 0.9rem 2rem;
    border-radius: 12px;
    font-size: 1rem; font-weight: 600;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3), 0 0 0 1px rgba(255,255,255,0.1);
    transition: all 0.3s ease;
    animation: fadeInUp 0.7s ease-out 0.3s both;
}

.google-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 40px rgba(26,115,232,0.3), 0 0 0 1px rgba(255,255,255,0.15);
}

.google-btn:active { transform: translateY(-1px); }

.google-icon { flex-shrink: 0; }

/* Note under button */
.hero-note {
    display: flex; align-items: center; justify-content: center; gap: 0.4rem;
    margin-top: 1.5rem;
    font-size: 0.82rem;
    color: var(--text-dim);
    animation: fadeInUp 0.7s ease-out 0.4s both;
}

/* === Sections === */
.section {
    padding: 5rem 1.5rem;
}

.section-dark {
    background: var(--bg-section);
}

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-title {
    font-size: 2rem; font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.75rem;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-muted);
}

/* === Steps === */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.step-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    position: relative;
    transition: all 0.3s ease;
}

.step-card:hover {
    border-color: rgba(26,115,232,0.3);
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.step-number {
    font-size: 3rem; font-weight: 800;
    background: linear-gradient(135deg, rgba(26,115,232,0.2), rgba(139,92,246,0.2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 1rem;
}

.step-icon {
    width: 52px; height: 52px;
    background: linear-gradient(135deg, rgba(26,115,232,0.15), rgba(139,92,246,0.15));
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    color: var(--primary-light);
    margin-bottom: 1rem;
}

.step-title {
    font-size: 1.15rem; font-weight: 600;
    margin-bottom: 0.5rem;
}

.step-desc {
    font-size: 0.92rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* === Features === */
.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.feature-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    transition: all 0.3s ease;
}

.feature-card:hover {
    border-color: rgba(139,92,246,0.3);
    transform: translateY(-3px);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.1rem; font-weight: 600;
    margin-bottom: 0.5rem;
}

.feature-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* === Footer === */
.footer {
    padding: 2rem 1.5rem;
    border-top: 1px solid var(--border);
}

.footer-inner {
    display: flex; align-items: center; justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-dim);
}

.footer-links {
    display: flex; align-items: center; gap: 0.75rem;
}

.footer-links a {
    color: var(--text-muted);
    transition: color 0.2s;
}
.footer-links a:hover { color: var(--primary-light); }

/* === Responsive === */
@media (max-width: 768px) {
    .steps-grid { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }
    .footer-inner { flex-direction: column; gap: 0.5rem; text-align: center; }
    .nav { gap: 0; }
    .nav-link { padding: 0.4rem 0.6rem; font-size: 0.8rem; }
    .hero { padding-top: 5rem; }
}

@media (max-width: 480px) {
    .hero-title { font-size: 2rem; }
    .hero-subtitle { font-size: 1rem; }
    .google-btn { padding: 0.8rem 1.5rem; font-size: 0.9rem; }
}