:root {
    color-scheme: light dark;

    --bg: #faf9f7;
    --bg-elevated: #ffffff;
    --bg-subtle: #f4f1ec;
    --border: #ebe6dd;
    --border-strong: #d9d2c4;
    --text: #2b2620;
    --text-muted: #7a7266;
    --text-faint: #a69d8d;

    --accent: #6d5efc;
    --accent-hover: #5c4ff0;
    --accent-text: #ffffff;
    --accent-soft: #efecff;
    --accent-soft-border: #dcd6ff;

    --success: #15803d;
    --success-bg: #f0fdf4;
    --success-border: #bbf7d0;
    --warning: #b45309;
    --warning-bg: #fffbeb;
    --warning-border: #fde68a;
    --danger: #dc2626;
    --danger-bg: #fef2f2;
    --danger-border: #fecaca;
    --info: #2563eb;
    --info-bg: #eff6ff;
    --info-border: #bfdbfe;

    --radius-sm: 8px;
    --radius: 12px;
    --radius-lg: 18px;

    --shadow-sm: 0 1px 2px rgba(43, 38, 32, 0.05);
    --shadow: 0 2px 8px rgba(43, 38, 32, 0.06), 0 1px 2px rgba(43, 38, 32, 0.04);
    --shadow-lg: 0 12px 32px rgba(43, 38, 32, 0.10);

    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Inter, Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'SF Mono', ui-monospace, 'Roboto Mono', Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #16141f;
        --bg-elevated: #1e1c2a;
        --bg-subtle: #262335;
        --border: #322e42;
        --border-strong: #423d58;
        --text: #f2f0f7;
        --text-muted: #a8a2bd;
        --text-faint: #746e8c;

        --accent: #9b8dff;
        --accent-hover: #ab9fff;
        --accent-text: #16141f;
        --accent-soft: #2a2540;
        --accent-soft-border: #3e3760;

        --success: #4ade80;
        --success-bg: #0f1f14;
        --success-border: #14532d;
        --warning: #fbbf24;
        --warning-bg: #221a08;
        --warning-border: #78350f;
        --danger: #f87171;
        --danger-bg: #23100f;
        --danger-border: #7f1d1d;
        --info: #60a5fa;
        --info-bg: #0e1a2b;
        --info-border: #1e3a8a;

        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
        --shadow: 0 2px 8px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
    }
}

[data-theme='dark'] {
    --bg: #16141f;
    --bg-elevated: #1e1c2a;
    --bg-subtle: #262335;
    --border: #322e42;
    --border-strong: #423d58;
    --text: #f2f0f7;
    --text-muted: #a8a2bd;
    --text-faint: #746e8c;

    --accent: #9b8dff;
    --accent-hover: #ab9fff;
    --accent-text: #16141f;
    --accent-soft: #2a2540;
    --accent-soft-border: #3e3760;

    --success: #4ade80;
    --success-bg: #0f1f14;
    --success-border: #14532d;
    --warning: #fbbf24;
    --warning-bg: #221a08;
    --warning-border: #78350f;
    --danger: #f87171;
    --danger-bg: #23100f;
    --danger-border: #7f1d1d;
    --info: #60a5fa;
    --info-bg: #0e1a2b;
    --info-border: #1e3a8a;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
}

[data-theme='light'] {
    --bg: #faf9f7;
    --bg-elevated: #ffffff;
    --bg-subtle: #f4f1ec;
    --border: #ebe6dd;
    --border-strong: #d9d2c4;
    --text: #2b2620;
    --text-muted: #7a7266;
    --text-faint: #a69d8d;

    --accent: #6d5efc;
    --accent-hover: #5c4ff0;
    --accent-text: #ffffff;
    --accent-soft: #efecff;
    --accent-soft-border: #dcd6ff;

    --success: #15803d;
    --success-bg: #f0fdf4;
    --success-border: #bbf7d0;
    --warning: #b45309;
    --warning-bg: #fffbeb;
    --warning-border: #fde68a;
    --danger: #dc2626;
    --danger-bg: #fef2f2;
    --danger-border: #fecaca;
    --info: #2563eb;
    --info-bg: #eff6ff;
    --info-border: #bfdbfe;

    --shadow-sm: 0 1px 2px rgba(43, 38, 32, 0.05);
    --shadow: 0 2px 8px rgba(43, 38, 32, 0.06), 0 1px 2px rgba(43, 38, 32, 0.04);
    --shadow-lg: 0 12px 32px rgba(43, 38, 32, 0.10);
}

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

html {
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

button, input, select {
    font-family: inherit;
}

a {
    color: inherit;
}

.icon {
    display: inline-block;
    vertical-align: middle;
    stroke: currentColor;
    fill: none;
    stroke-width: 1.75;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-strong);
    border-top-color: var(--text);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
    flex-shrink: 0;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 18px;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent);
    color: var(--accent-text);
    box-shadow: 0 1px 2px rgba(43, 38, 32, 0.06);
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
}

.btn-secondary {
    background: var(--bg-elevated);
    color: var(--text);
    border-color: var(--border-strong);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-subtle);
    border-color: var(--text-faint);
}

.page {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: radial-gradient(680px circle at 50% 0%, var(--accent-soft) 0%, transparent 65%);
}

.top-bar {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 560px;
    margin: 0 auto;
    width: 100%;
}

.brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text);
}

.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-strong);
    background: var(--bg-elevated);
    color: var(--text-muted);
    cursor: pointer;
    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.theme-toggle:hover {
    background: var(--bg-subtle);
    color: var(--text);
}

.hero {
    flex: 1;
    max-width: 560px;
    width: 100%;
    margin: 0 auto;
    padding: 64px 24px 48px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border-radius: 999px;
    background: var(--accent-soft);
    border: 1px solid var(--accent-soft-border);
    color: var(--accent);
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 2rem;
    font-weight: 650;
    letter-spacing: -0.02em;
    line-height: 1.2;
    color: var(--text);
}

.hero-sub {
    margin-top: 12px;
    font-size: 1rem;
    color: var(--text-muted);
    max-width: 440px;
    line-height: 1.55;
}

@media (min-width: 640px) {
    .hero h1 {
        font-size: 2.5rem;
    }
}

.card {
    width: 100%;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    margin-top: 40px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    box-shadow: var(--shadow);
    text-align: left;
}

.card label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
}

.upload-area {
    border: 2px dashed var(--border-strong);
    border-radius: var(--radius);
    padding: 40px 24px;
    text-align: center;
    cursor: pointer;
    background: var(--bg);
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    transition: border-color 0.15s ease, background-color 0.15s ease;
}

.upload-area:hover {
    border-color: var(--accent);
    background: var(--accent-soft);
}

.upload-area .icon {
    color: var(--text-faint);
    margin-bottom: 12px;
}

.hash-select {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.95rem;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    background: var(--bg);
    color: var(--text);
}

.hash-select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.input-field {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.95rem;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    background: var(--bg);
    color: var(--text);
    resize: vertical;
    font-family: inherit;
}

.input-field:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

.qr-code {
    display: flex;
    justify-content: center;
    padding: 12px;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.qr-code img {
    display: block;
    max-width: 100%;
    height: auto;
}

.card > .btn {
    width: 100%;
    padding: 12px 18px;
}

.progress-bar {
    display: none;
    width: 100%;
    height: 8px;
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: 999px;
    overflow: hidden;
}

.progress-bar-inner {
    height: 100%;
    width: 0;
    background: var(--accent);
    transition: width 0.2s ease;
}

.progress-info {
    display: none;
    font-size: 0.8rem;
    color: var(--text-muted);
    text-align: center;
}

.message {
    display: none;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    text-align: center;
    border: 1px solid transparent;
}

.message.show {
    display: block;
}

.message.error {
    background: var(--danger-bg);
    border-color: var(--danger-border);
    color: var(--danger);
}

.message.success {
    background: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success);
}

.result-card {
    display: none;
    background: var(--bg-subtle);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px;
}

.result-card.show {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.result-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.result-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.result-value {
    display: block;
    flex: 1;
    min-width: 0;
    padding: 10px 12px;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text);
    overflow-wrap: break-word;
    word-break: break-all;
}

.feature-list {
    list-style: none;
    margin-top: 40px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px 20px;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.feature-list .icon {
    color: var(--accent);
}

.api-docs-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 24px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
    text-decoration: none;
}

.api-docs-link:hover {
    color: var(--accent);
}

@media (max-width: 640px) {
    .result-row {
        flex-direction: column;
        align-items: stretch;
    }

    .card > .btn,
    .result-row .btn {
        width: 100%;
    }
}