/* ============================================
   APP.CSS - CSS tổng, dùng cho toàn bộ website
   ============================================ */

/* --- Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;800;900&family=Syne:wght@800&family=Bangers&display=swap');

@font-face {
    font-family: 'Redzone';
    src: url('../fonts/redzone.ttf') format('truetype');
    font-display: swap;
}

/*
 * Font system:
 *   --font-body:    Inter       → body text, UI
 *   --font-heading: Redzone     → headings (h1, h2), logo
 *   --font-hero:    Bangers     → hero title only
 *   --font-mono:    monospace   → code, textarea
 *
 * Thay đổi font? Sửa ở đây, tất cả trang tự cập nhật.
 */

:root {
    --font-body: 'Inter', sans-serif;
    --font-heading: 'Redzone', 'Syne', sans-serif;
    --font-hero: 'Bangers', cursive;
    --font-mono: 'Courier New', monospace;
}

/* --- Variables --- */
:root {
    --bg-dark: #0a0a0a;
    --bg-card: #141414;
    --bg-card-hover: #1a1a1a;
    --accent: #dc2626;
    --accent-light: #ef4444;
}

/* --- Base --- */
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-heading);
    background-color: var(--bg-dark);
    color: #a3a3a3;
    overflow-x: hidden;
}

h1, h2, .logo-text { font-family: var(--font-heading); }
.hero-title { font-family: var(--font-hero); letter-spacing: 0.05em; }

/* --- Navbar --- */
.glass-nav {
    background: rgba(10, 10, 10, 0.15);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s;
}

.glass-nav.scrolled {
    background: rgba(10, 10, 10, 0.95);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
    border-color: rgba(255, 255, 255, 0.08);
}

/* --- Card --- */
.card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s;
    overflow: hidden;
}

.card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(220, 38, 38, 0.2);
}

.card img { transition: transform 0.5s; }
.card:hover img { transform: scale(1.05); }

/* --- Social Icons --- */
.social-icon {
    width: 38px;
    height: 38px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
}

.social-icon:hover {
    background: var(--accent);
    transform: scale(1.05);
}

/* --- Section Label --- */
.section-label {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.section-label::before {
    content: '';
    width: 28px;
    height: 2px;
    background: var(--accent);
}

/* --- Badge --- */
.badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.6rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* --- Video --- */
.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    border-radius: 8px;
    overflow: hidden;
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* --- Steps --- */
.step-number {
    width: 40px;
    height: 40px;
    min-width: 40px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    font-size: 0.9rem;
}

/* --- Animation --- */
.fade-up {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s, transform 0.5s;
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Content area - dot pattern --- */
.content-area {
    position: relative;
    background: var(--bg-dark);
}

.content-area::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 24px 24px;
    pointer-events: none;
    z-index: 0;
    mask-image: linear-gradient(to bottom, transparent 0%, black 80px);
    -webkit-mask-image: linear-gradient(to bottom, transparent 0%, black 80px);
}

.content-area > * {
    position: relative;
    z-index: 1;
}