:root {
    --navy: #12203b;
    --navy-2: #1c3660;
    --gold: #c99a3f;
    --gold-light: #e8c682;
    --ink: #1a1f2b;
    --muted: #5b6472;
    --bg: #eae8e1;
    --card: #ffffff;
    --border: #d8d5cb;
    --radius: 14px;
    --shadow: 0 10px 30px rgba(18, 32, 59, 0.09);
    --max: 1400px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, Arial, sans-serif;
    background: var(--bg);
    color: var(--ink);
    line-height: 1.6;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.container { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
    position: sticky; top: 0; z-index: 100;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.brand { font-size: 1.3rem; font-weight: 700; letter-spacing: .3px; color: var(--navy); }
.brand span { color: var(--gold); }
.nav { display: flex; gap: 30px; align-items: center; }
.nav a { font-size: .95rem; font-weight: 600; color: var(--navy); opacity: .8; transition: opacity .2s; }
.nav a:hover { opacity: 1; }
.nav a.locked { display: inline-flex; align-items: center; gap: 6px; }
.nav-toggle { display: none; }

@media (max-width: 860px) {
    .nav { position: fixed; inset: 76px 0 0 0; background: var(--bg); flex-direction: column;
        padding: 30px 24px; gap: 22px; transform: translateY(-110%); transition: transform .25s ease; }
    .nav.open { transform: translateY(0); }
    .nav-toggle { display: block; background: none; border: none; font-size: 1.6rem; cursor: pointer; color: var(--navy); }
}

/* Hero */
.hero { padding: 70px 0 40px; }
.hero .container { display: grid; grid-template-columns: 1.1fr .9fr; gap: 50px; align-items: center; }
.hero-eyebrow { color: var(--gold); font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; font-size: .8rem; margin-bottom: 14px; }
.hero h1 { font-size: 2.6rem; line-height: 1.2; color: var(--navy); margin: 0 0 20px; }
.hero p.lead { color: var(--muted); font-size: 1.1rem; margin-bottom: 30px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-photo { position: relative; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); aspect-ratio: 4/5; }
.hero-photo img { width: 100%; height: 100%; object-fit: cover; }

/* Buttons */
.btn { display: inline-block; padding: 13px 26px; border-radius: 999px; font-weight: 700; font-size: .95rem; border: 2px solid transparent; cursor: pointer; }
.btn-primary { background: var(--navy); color: #fff; }
.btn-primary:hover { background: var(--navy-2); }
.btn-ghost { border-color: var(--navy); color: var(--navy); background: transparent; }
.btn-ghost:hover { background: var(--navy); color: #fff; }
.btn-gold { background: var(--gold); color: #21170a; }

/* Section */
.section { padding: 90px 0; }
.section-alt { background: #f4f3ec; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { max-width: 760px; margin: 0 auto 48px; text-align: center; }
.section-head .eyebrow { color: var(--gold); font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; font-size: .78rem; margin-bottom: 10px; }
.section-head h2 { font-size: 2rem; color: var(--navy); margin: 0 0 14px; }
.section-head p { color: var(--muted); margin: 0; }

/* About */
.about-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: 56px; align-items: center; }
.about-photo { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.about-text p { color: var(--muted); margin-bottom: 18px; }
.badges { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.badge { display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px; border-radius: 999px; background: #eef1f6; color: var(--navy); font-size: .85rem; font-weight: 600; border: 1px solid var(--border); }

/* Stats */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 56px; }
.stat { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 20px; text-align: center; }
.stat .num { font-size: 2.1rem; font-weight: 800; color: var(--navy); }
.stat .label { color: var(--muted); font-size: .85rem; margin-top: 6px; }

/* Books */
.books-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 22px; }
.book-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); transition: transform .2s; }
.book-card:hover { transform: translateY(-6px); }
.book-card img { aspect-ratio: 3/4; object-fit: cover; width: 100%; }
.book-card .book-label { padding: 12px 14px; font-weight: 700; font-size: .85rem; color: var(--navy); text-align: center; }

/* Content tabs (AI & Education) */
.content-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.content-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); }
.content-card .tag { color: var(--gold); font-weight: 700; font-size: .78rem; letter-spacing: 1px; text-transform: uppercase; }
.content-card h3 { color: var(--navy); font-size: 1.3rem; margin: 12px 0; }
.content-card p { color: var(--muted); margin-bottom: 20px; }

/* Locked section */
.locked-card { background: linear-gradient(135deg, var(--navy), var(--navy-2)); color: #fff; border-radius: var(--radius); padding: 56px; text-align: center; }
.locked-card .lock-icon { font-size: 2.4rem; margin-bottom: 14px; }
.locked-card h2 { margin: 0 0 12px; font-size: 1.8rem; }
.locked-card p { color: #cfd8e8; max-width: 480px; margin: 0 auto 26px; }

/* Footer */
.site-footer { background: var(--navy); color: #dbe1ec; padding: 56px 0 26px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.site-footer h4 { color: #fff; margin: 0 0 16px; font-size: 1rem; }
.site-footer a { color: #b7c1d4; display: block; margin-bottom: 10px; font-size: .92rem; }
.site-footer a:hover { color: #fff; }
.social-row { display: flex; gap: 12px; flex-wrap: wrap; }
.social-row a { background: rgba(255,255,255,.08); padding: 9px 16px; border-radius: 999px; margin: 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.12); padding-top: 22px; font-size: .82rem; color: #8fa0bb; text-align: center; }

/* Login / Admin */
.auth-wrap { min-height: 70vh; display: flex; align-items: center; justify-content: center; padding: 60px 24px; }
.auth-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 44px; width: 100%; max-width: 400px; }
.auth-card h1 { color: var(--navy); font-size: 1.5rem; margin: 0 0 8px; }
.auth-card p.sub { color: var(--muted); margin: 0 0 28px; font-size: .9rem; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: .85rem; font-weight: 600; color: var(--navy); margin-bottom: 7px; }
.field input, .field textarea { width: 100%; padding: 12px 14px; border: 1px solid var(--border); border-radius: 9px; font-size: .95rem; font-family: inherit; }
.field textarea { resize: vertical; min-height: 90px; }
.alert { padding: 12px 16px; border-radius: 9px; font-size: .88rem; margin-bottom: 18px; }
.alert-error { background: #fdecec; color: #a52121; border: 1px solid #f5c6c6; }
.alert-success { background: #e9f7ee; color: #216b3f; border: 1px solid #b9e5c8; }

.admin-shell { max-width: 900px; margin: 0 auto; padding: 50px 24px 90px; }
.admin-topbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 34px; }
.admin-topbar h1 { color: var(--navy); margin: 0; font-size: 1.6rem; }
.panel { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 30px; margin-bottom: 30px; box-shadow: var(--shadow); }
.panel h2 { color: var(--navy); font-size: 1.15rem; margin: 0 0 20px; }
.table-list { width: 100%; border-collapse: collapse; }
.table-list th, .table-list td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--border); font-size: .9rem; }
.table-list td.actions { text-align: right; white-space: nowrap; }
.link-del { color: #a52121; font-weight: 700; font-size: .85rem; }
.form-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }

@media (max-width: 860px) {
    .hero .container, .about-grid, .content-grid, .footer-grid { grid-template-columns: 1fr; }
    .stats { grid-template-columns: repeat(2, 1fr); }
    .books-grid { grid-template-columns: repeat(2, 1fr); }
    .form-row { grid-template-columns: 1fr; }
}