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

:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --success: #16a34a;
    --radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}

/* Header */
header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
}

header .container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary);
}

.tagline {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* Main */
main {
    flex: 1;
    padding: 48px 0 64px;
}

/* Hero */
.hero {
    text-align: center;
    margin-bottom: 48px;
}

.hero h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 1.15rem;
    color: var(--text-muted);
    margin-bottom: 32px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

/* Download button */
.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    background: var(--primary);
    color: white;
    text-decoration: none;
    padding: 16px 36px;
    border-radius: var(--radius);
    font-size: 1.15rem;
    font-weight: 600;
    transition: background 0.15s, transform 0.1s;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.btn-download:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
}

.btn-download:active {
    transform: translateY(0);
}

.dl-icon::before {
    content: "\2B07";
    font-size: 1.3rem;
}

.dl-size {
    display: block;
    font-size: 0.8rem;
    font-weight: 400;
    opacity: 0.85;
}

/* Alt platforms */
.alt-platforms {
    margin-top: 16px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.alt-link {
    color: var(--primary);
    text-decoration: none;
    margin-left: 8px;
    font-weight: 500;
}

.alt-link:hover {
    text-decoration: underline;
}

/* Config section */
.config-section {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 48px;
    text-align: center;
}

.config-section h3 {
    font-size: 1rem;
    margin-bottom: 16px;
    font-weight: 600;
}

.config-box {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #f1f5f9;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 16px;
    margin-bottom: 12px;
}

.config-box code {
    flex: 1;
    font-family: "SF Mono", "Fira Code", "Consolas", monospace;
    font-size: 0.85rem;
    word-break: break-all;
    text-align: left;
    user-select: all;
}

.btn-copy {
    background: var(--primary);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: background 0.15s;
}

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

.btn-copy.copied {
    background: var(--success);
}

.config-help {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Steps */
.steps {
    margin-bottom: 48px;
}

.steps h2 {
    text-align: center;
    font-size: 1.4rem;
    margin-bottom: 24px;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.step {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px 20px;
    text-align: center;
}

.step-num {
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 12px;
}

.step h3 {
    font-size: 1rem;
    margin-bottom: 8px;
}

.step p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Trust / warnings */
.trust-section {
    margin-bottom: 32px;
}

.trust-section details {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-bottom: 8px;
}

.trust-section summary {
    font-weight: 600;
    cursor: pointer;
    font-size: 0.95rem;
}

.trust-section details p {
    margin-top: 12px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Mobile message */
.mobile-message {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
}

.mobile-message p {
    font-size: 1.05rem;
    margin-bottom: 12px;
}

.mobile-message p:last-child {
    margin-bottom: 0;
    color: var(--text-muted);
}

/* Footer */
footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 20px 0;
    text-align: center;
}

footer p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Responsive */
@media (max-width: 640px) {
    .hero h1 { font-size: 1.6rem; }
    .subtitle { font-size: 1rem; }
    .btn-download { padding: 14px 28px; font-size: 1rem; }
    .steps-grid { grid-template-columns: 1fr; }
    main { padding: 32px 0 48px; }
}