:root {
    --bg: #F8FAFC;
    --card-bg: #FFFFFF;
    --text: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --primary: #2563EB;
    --primary-hover: #1D4ED8;
    --primary-light: rgba(37,99,235,0.06);
    --success: #10B981;
    --success-light: rgba(16,185,129,0.08);
    --danger: #EF4444;
    --warning: #F59E0B;
    --border: #E2E8F0;
    --border-light: #F1F5F9;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.06), 0 2px 4px rgba(0,0,0,0.04);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.08), 0 4px 8px rgba(0,0,0,0.04);
    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 14px;
    --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
    --max-width: 1280px;
    --transition: 0.2s cubic-bezier(0.4,0,0.2,1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex; flex-direction: column;
}

.app-header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 100;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.header-content {
    max-width: var(--max-width);
    margin: 0 auto; padding: 14px 24px;
    display: flex; align-items: center; justify-content: space-between;
}
.header-brand {
    display: flex; align-items: center; gap: 12px;
}
.header-brand svg { color: var(--primary); }
.header-brand h1 {
    font-size: 18px; font-weight: 700;
    letter-spacing: -0.3px;
}
.header-ver {
    font-size: 11px; color: var(--text-muted);
    background: var(--border-light);
    padding: 3px 10px; border-radius: 99px;
    font-family: var(--font-mono);
}

.app-main {
    flex: 1; max-width: var(--max-width);
    margin: 0 auto; padding: 32px 24px 48px;
    width: 100%;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition);
}
.card:hover { box-shadow: var(--shadow-md); }
.card-header {
    padding: 22px 28px 0;
}
.card-header h2 {
    font-size: 17px; font-weight: 700; letter-spacing: -0.2px;
}
.card-subtitle {
    font-size: 13px; color: var(--text-muted);
    display: block; margin-top: 3px;
}
.card-body { padding: 24px 28px 28px; }

.form-grid { display: flex; flex-direction: column; gap: 18px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
    font-size: 13px; font-weight: 600; color: var(--text-secondary);
    letter-spacing: 0.01em;
}
.form-row-3 {
    display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 18px;
}

.input {
    width: 100%; padding: 10px 14px;
    font-size: 14px; font-family: inherit;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    color: var(--text);
    transition: all var(--transition);
    outline: none;
}
.input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}
.input::placeholder { color: var(--text-muted); }

.input-with-hint { position: relative; }
.input-hint {
    font-size: 11px; color: var(--text-muted);
    margin-top: 4px;
}
.input-hint code {
    background: var(--border-light);
    padding: 1px 6px; border-radius: 3px;
    font-family: var(--font-mono); font-size: 11px;
}

.url-history-wrap { position: relative; }
.input-with-history { position: relative; display: flex; }
.input-with-history .input { padding-right: 38px; flex: 1; }
.btn-history-toggle {
    position: absolute; right: 1px; top: 1px; bottom: 1px;
    width: 34px; display: flex; align-items: center; justify-content: center;
    background: none; border: none; cursor: pointer;
    color: var(--text-muted); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    transition: all var(--transition);
}
.btn-history-toggle:hover { background: var(--primary-light); color: var(--primary); }

.url-history-dropdown {
    position: absolute; left: 0; right: 0; top: 100%;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    box-shadow: var(--shadow-lg);
    z-index: 50; max-height: 240px;
    display: flex; flex-direction: column;
    animation: dropIn 0.15s ease;
}
@keyframes dropIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

.url-history-list { flex: 1; overflow-y: auto; }
.url-history-item {
    display: flex; align-items: center; justify-content: space-between;
    padding: 9px 14px; font-size: 13px; cursor: pointer;
    transition: background var(--transition);
    border-bottom: 1px solid var(--border-light);
}
.url-history-item:last-child { border-bottom: none; }
.url-history-item:hover { background: var(--primary-light); }
.url-history-item .url-text {
    flex: 1; overflow: hidden; text-overflow: ellipsis;
    white-space: nowrap; font-family: var(--font-mono);
    font-size: 12px; color: var(--text-secondary);
}
.url-history-item .url-count {
    font-size: 11px; color: var(--text-muted); margin: 0 8px;
    flex-shrink: 0;
}
.url-history-item .url-del {
    flex-shrink: 0; width: 24px; height: 24px;
    display: flex; align-items: center; justify-content: center;
    background: none; border: none; cursor: pointer;
    color: var(--text-muted); border-radius: 4px;
    font-size: 14px; line-height: 1; transition: all var(--transition);
}
.url-history-item .url-del:hover { background: rgba(239,68,68,0.1); color: var(--danger); }
.url-history-footer {
    border-top: 1px solid var(--border-light);
    padding: 6px 12px; text-align: right;
}
.url-history-empty {
    padding: 20px 14px; text-align: center;
    font-size: 12px; color: var(--text-muted);
}

.url-history-wrap.focused .input {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
    border-bottom-left-radius: 0; border-bottom-right-radius: 0;
}

.form-actions {
    display: flex; gap: 12px; align-items: center;
    margin-top: 8px; flex-wrap: wrap;
}

.btn {
    display: inline-flex; align-items: center; gap: 7px;
    padding: 9px 18px;
    font-size: 14px; font-weight: 600; font-family: inherit;
    border: 1px solid transparent;
    border-radius: var(--radius-sm); cursor: pointer;
    transition: all var(--transition); outline: none;
    white-space: nowrap; letter-spacing: 0.01em;
}
.btn:active { transform: scale(0.97); }
.btn-lg { padding: 11px 24px; font-size: 15px; border-radius: var(--radius); }
.btn-sm { padding: 6px 14px; font-size: 12px; }

.btn-primary {
    background: var(--primary); color: #fff;
    border-color: var(--primary);
    box-shadow: 0 2px 8px rgba(37,99,235,0.3);
}
.btn-primary:hover { background: var(--primary-hover); box-shadow: 0 4px 16px rgba(37,99,235,0.35); }

.btn-outline {
    background: var(--card-bg); color: var(--text-secondary);
    border-color: var(--border);
}
.btn-outline:hover {
    background: var(--primary-light);
    border-color: var(--primary); color: var(--primary);
}
.btn-outline:disabled {
    opacity: 0.45; cursor: not-allowed;
}
.btn-outline:disabled:hover {
    background: var(--card-bg); border-color: var(--border); color: var(--text-secondary);
}

.btn-ghost {
    background: none; color: var(--text-muted);
    border-color: transparent;
}
.btn-ghost:hover {
    background: var(--border-light); color: var(--text);
}

.stats-section { margin-top: 24px; }
.stats-bar {
    display: flex; gap: 16px; flex-wrap: wrap;
}
.stat-item {
    flex: 1; min-width: 160px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    box-shadow: var(--shadow-sm);
}
.stat-label {
    font-size: 12px; color: var(--text-muted);
    text-transform: uppercase; letter-spacing: 0.04em;
    display: block; margin-bottom: 4px;
}
.stat-value {
    font-size: 22px; font-weight: 700; font-family: var(--font-mono);
    color: var(--primary); letter-spacing: -0.5px;
}
.stat-url {
    font-size: 14px;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    display: block; max-width: 320px;
}

.progress-section { margin-top: 20px; }
.progress-bar-wrap {
    display: flex; align-items: center; gap: 14px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius); padding: 14px 20px;
}
.progress-bar {
    flex: 1; height: 8px; border-radius: 99px;
    background: var(--border-light); overflow: hidden;
}
.progress-fill {
    height: 100%; border-radius: 99px;
    background: linear-gradient(90deg, #2563EB, #60A5FA);
    width: 0%; transition: width 0.3s ease;
}
.progress-text {
    font-size: 13px; font-weight: 600; color: var(--primary);
    white-space: nowrap; font-family: var(--font-mono);
}

.result-section { margin-top: 32px; }
.result-header {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 16px;
}
.result-header h2 {
    font-size: 18px; font-weight: 700; letter-spacing: -0.3px;
}
.result-header-right {
    display: flex; align-items: center; gap: 10px;
}
.result-count {
    font-size: 13px; color: var(--text-muted);
    font-family: var(--font-mono);
}

.qr-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 18px;
}

.qr-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
    display: flex; flex-direction: column;
}
.qr-card:hover {
    box-shadow: 0 8px 30px rgba(37,99,235,0.12);
    transform: translateY(-3px);
    border-color: var(--primary);
}
.qr-card-image {
    width: 100%; aspect-ratio: 1;
    display: flex; align-items: center; justify-content: center;
    background: #fff;
    padding: 16px;
    position: relative;
}
.qr-card-image img {
    width: 100%; height: 100%;
    object-fit: contain;
    image-rendering: pixelated;
}
.qr-card-info {
    padding: 12px 14px 10px;
    border-top: 1px solid var(--border-light);
    display: flex; flex-direction: column; gap: 4px;
}
.qr-card-url {
    font-size: 11px; color: var(--text-muted);
    overflow: hidden; text-overflow: ellipsis;
    white-space: nowrap; font-family: var(--font-mono);
}
.qr-card-actions {
    display: flex; gap: 6px;
    padding: 0 14px 14px;
}
.qr-card-actions .btn {
    flex: 1; justify-content: center;
    padding: 7px 10px; font-size: 12px;
}

.empty-state {
    grid-column: 1 / -1;
    text-align: center; padding: 60px 20px;
    color: var(--text-muted);
}
.empty-icon { font-size: 48px; margin-bottom: 12px; opacity: 0.3; }

.app-footer {
    text-align: center; padding: 20px;
    font-size: 12px; color: var(--text-muted);
    border-top: 1px solid var(--border);
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}
.qr-card { animation: fadeUp 0.4s ease both; }

@media (max-width: 768px) {
    .header-content { padding: 12px 16px; }
    .header-brand h1 { font-size: 16px; }
    .app-main { padding: 20px 14px 40px; }
    .card-header { padding: 18px 18px 0; }
    .card-body { padding: 18px; }
    .form-row-3 { grid-template-columns: 1fr; }
    .qr-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 12px; }
    .form-actions { flex-direction: column; }
    .form-actions .btn { width: 100%; justify-content: center; }
    .stats-bar { flex-direction: column; }
    .stat-url { max-width: 100%; }
}
@media (max-width: 480px) {
    .qr-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .qr-card-image { padding: 10px; }
    .qr-card-actions { padding: 0 10px 10px; }
    .qr-card-actions .btn { font-size: 11px; padding: 5px 6px; }
}