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

:root {
    --navy: #1a2332;
    --navy-light: #243447;
    --blue: #3b82f6;
    --blue-dark: #2563eb;
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-900: #0f172a;
    --green: #10b981;
    --purple: #8b5cf6;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--gray-900);
    background: var(--white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

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

/* ── Layout ──────────────────────────────────────────── */
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

.container--narrow {
    max-width: 720px;
}

/* ── Header / Nav ────────────────────────────────────── */
.site-header {
    background: var(--navy);
    color: var(--white);
    padding: 16px 0;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-header__brand {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.01em;
}

.site-header__brand:hover {
    text-decoration: none;
    opacity: 0.9;
}

.site-nav {
    display: flex;
    gap: 24px;
}

.site-nav a {
    color: var(--gray-300);
    font-size: 0.875rem;
    font-weight: 500;
    transition: color 0.15s;
}

.site-nav a:hover {
    color: var(--white);
    text-decoration: none;
}

/* ── Hero ────────────────────────────────────────────── */
.hero {
    background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
    color: var(--white);
    padding: 80px 0 64px;
    text-align: center;
}

.hero h1 {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.hero p {
    font-size: 1.125rem;
    color: var(--gray-300);
    max-width: 560px;
    margin: 0 auto;
}

/* ── Section ─────────────────────────────────────────── */
.section {
    padding: 64px 0;
}

.section--gray {
    background: var(--gray-50);
}

.section__title {
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 40px;
    letter-spacing: -0.01em;
}

/* ── App Cards (Homepage) ────────────────────────────── */
.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.app-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
    transition: box-shadow 0.2s, transform 0.2s;
}

.app-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.app-card__icon {
    width: 64px;
    height: 64px;
    border-radius: 14px;
    background: var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: 20px;
}

.app-card__icon--topik {
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    color: var(--white);
}

.app-card__icon--dnb {
    background: linear-gradient(135deg, #10b981, #3b82f6);
    color: var(--white);
}

.app-card__name {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.app-card__tagline {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 16px;
}

.app-card__desc {
    font-size: 0.9375rem;
    color: var(--gray-600);
    margin-bottom: 20px;
}

.app-card__link {
    font-size: 0.875rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.app-card__link::after {
    content: '\2192';
}

/* ── App Page Layout ─────────────────────────────────── */
.app-hero {
    background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
    color: var(--white);
    padding: 64px 0 48px;
}

.app-hero__header {
    display: flex;
    align-items: center;
    gap: 24px;
    margin-bottom: 16px;
}

.app-hero__icon {
    width: 80px;
    height: 80px;
    border-radius: 18px;
    background: rgba(255,255,255,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.25rem;
    flex-shrink: 0;
}

.app-hero__title {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.app-hero__tagline {
    font-size: 1.125rem;
    color: var(--gray-300);
    margin-bottom: 24px;
}

.app-hero__cta {
    display: inline-block;
}

.app-hero__cta img {
    height: 48px;
}

/* ── Feature List ────────────────────────────────────── */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.feature {
    padding: 24px;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
}

.feature__icon {
    font-size: 1.5rem;
    margin-bottom: 12px;
}

.feature__title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature__desc {
    font-size: 0.875rem;
    color: var(--gray-600);
    line-height: 1.5;
}

/* ── Privacy Policy ──────────────────────────────────── */
.policy {
    padding: 48px 0 64px;
}

.policy h1 {
    font-size: 1.5rem;
    font-weight: 700;
    border-bottom: 1px solid var(--gray-200);
    padding-bottom: 12px;
    margin-bottom: 24px;
}

.policy h2 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-top: 32px;
    margin-bottom: 12px;
}

.policy h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-top: 24px;
    margin-bottom: 8px;
}

.policy p,
.policy li {
    font-size: 0.9375rem;
    color: var(--gray-700);
    margin-bottom: 12px;
}

.policy ul {
    padding-left: 24px;
    margin-bottom: 16px;
}

.policy li {
    margin-bottom: 6px;
}

.policy a {
    word-break: break-all;
}

/* ── Footer ──────────────────────────────────────────── */
.site-footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: 40px 0;
    font-size: 0.875rem;
}

.site-footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    text-align: center;
}

.site-footer__company {
    font-weight: 600;
    color: var(--white);
}

.site-footer a {
    color: var(--gray-300);
}

.site-footer a:hover {
    color: var(--white);
}

/* ── Utilities ───────────────────────────────────────── */
.text-center { text-align: center; }
.mt-4 { margin-top: 16px; }
.mt-8 { margin-top: 32px; }
.mb-4 { margin-bottom: 16px; }

/* ── Responsive ──────────────────────────────────────── */
@media (max-width: 640px) {
    .hero {
        padding: 48px 0 40px;
    }

    .hero h1 {
        font-size: 1.75rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .app-grid {
        grid-template-columns: 1fr;
    }

    .app-hero {
        padding: 40px 0 32px;
    }

    .app-hero__header {
        flex-direction: column;
        text-align: center;
    }

    .app-hero__title {
        font-size: 1.5rem;
    }

    .section {
        padding: 40px 0;
    }

    .site-nav {
        gap: 16px;
    }

    .features {
        grid-template-columns: 1fr;
    }
}