:root {
    --primary: #1a365d;
    --primary-light: #2b6cb0;
    --primary-dark: #0f2440;
    --accent: #d69e2e;
    --accent-light: #ecc94b;
    --bg: #f7fafc;
    --bg-card: #ffffff;
    --text: #2d3748;
    --text-light: #718096;
    --text-inverse: #f7fafc;
    --success: #38a169;
    --success-bg: #f0fff4;
    --success-border: #c6f6d5;
    --error: #e53e3e;
    --error-bg: #fff5f5;
    --error-border: #fed7d7;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 4px 6px -1px rgba(0,0,0,.1), 0 2px 4px -1px rgba(0,0,0,.06);
    --shadow-lg: 0 20px 25px -5px rgba(0,0,0,.1), 0 10px 10px -5px rgba(0,0,0,.04);
    --transition: 200ms ease;
}

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

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ── Header ─────────────────────────────────────── */

.site-header {
    background: var(--primary);
    color: var(--text-inverse);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 8px rgba(0,0,0,.15);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: inherit;
}

.logo-img {
    height: 38px;
    width: auto;
    border-radius: 5px;
    display: block;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-brand {
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.01em;
    line-height: 1.2;
}

.logo-tagline {
    font-size: 0.75rem;
    opacity: 0.7;
    line-height: 1.2;
}

.lang-switcher {
    display: flex;
    gap: 4px;
    background: rgba(255,255,255,.1);
    padding: 3px;
    border-radius: 8px;
}

.lang-btn {
    background: transparent;
    border: none;
    color: rgba(255,255,255,.6);
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.35rem 0.65rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition);
}

.lang-btn:hover {
    color: rgba(255,255,255,.9);
    background: rgba(255,255,255,.1);
}

.lang-btn.active {
    background: rgba(255,255,255,.2);
    color: #fff;
}

/* ── Hero ───────────────────────────────────────── */

.hero {
    text-align: center;
    padding: 3.5rem 0 2rem;
}

.hero-icon {
    color: var(--accent);
    margin-bottom: 1rem;
}

.hero-icon svg {
    display: inline-block;
}

.hero h1 {
    font-family: 'Playfair Display', serif;
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.hero-sub {
    color: var(--text-light);
    font-size: 1.05rem;
    max-width: 480px;
    margin: 0 auto;
}

/* ── Verify Section ─────────────────────────────── */

.verify-section {
    padding-bottom: 4rem;
}

.verify-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.verify-form {
    width: 100%;
}

.input-group {
    display: flex;
    gap: 0.75rem;
}

.cert-input {
    flex: 1;
    padding: 0.85rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: var(--radius-sm);
    font-family: 'Inter', sans-serif;
    font-size: 0.95rem;
    color: var(--text);
    transition: border-color var(--transition);
    outline: none;
}

.cert-input:focus {
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(43,108,176,.15);
}

.cert-input::placeholder {
    color: #a0aec0;
}

.verify-btn {
    padding: 0.85rem 1.75rem;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-family: 'Inter', sans-serif;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition);
    white-space: nowrap;
}

.verify-btn:hover {
    background: var(--primary-light);
}

.verify-btn:active {
    transform: scale(0.98);
}

/* ── Result ─────────────────────────────────────── */

.result {
    margin-top: 1.5rem;
    transition: opacity 300ms ease, transform 300ms ease;
}

.result.hidden {
    display: none;
}

.result-card {
    border-radius: var(--radius);
    padding: 1.75rem;
    box-shadow: var(--shadow);
    animation: slideUp 300ms ease;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-card.valid {
    background: var(--success-bg);
    border: 2px solid var(--success-border);
}

.result-card.invalid {
    background: var(--error-bg);
    border: 2px solid var(--error-border);
}

.result-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

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

.result-icon.valid-icon {
    color: var(--success);
}

.result-icon.invalid-icon {
    color: var(--error);
}

.result-title {
    font-size: 1.25rem;
    font-weight: 700;
}

.result-card.valid .result-title {
    color: #276749;
}

.result-card.invalid .result-title {
    color: #c53030;
}

.result-details {
    display: grid;
    gap: 0.65rem;
}

.result-row {
    display: flex;
    gap: 0.75rem;
    font-size: 0.95rem;
}

.result-label {
    font-weight: 600;
    color: var(--text-light);
    min-width: 140px;
    flex-shrink: 0;
}

.result-value {
    color: var(--text);
}

.result-actions {
    margin-top: 1.25rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--success-border);
}

.view-cert-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    background: var(--primary);
    color: #fff;
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.9rem;
    transition: background var(--transition);
}

.view-cert-btn:hover {
    background: var(--primary-light);
}

.invalid-message {
    color: #c53030;
    font-size: 0.95rem;
}

/* ── Footer ─────────────────────────────────────── */

.site-footer {
    margin-top: auto;
    padding: 1.5rem 0;
    text-align: center;
    color: var(--text-light);
    font-size: 0.85rem;
    border-top: 1px solid #e2e8f0;
}

/* ── Responsive ─────────────────────────────────── */

@media (max-width: 600px) {
    .hero h1 {
        font-size: 1.65rem;
    }

    .hero-sub {
        font-size: 0.95rem;
    }

    .input-group {
        flex-direction: column;
    }

    .verify-btn {
        width: 100%;
    }

    .result-row {
        flex-direction: column;
        gap: 0.15rem;
    }

    .result-label {
        min-width: unset;
        font-size: 0.82rem;
    }

    .logo-tagline {
        display: none;
    }
}