:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --accent: #8b5cf6;
    --text-1: #1e293b;
    --text-2: #64748b;
    --text-3: #94a3b8;
    --border: #e2e8f0;
    --bg-card: #ffffff;
    --danger: #ef4444;
    --success: #10b981;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --shadow-card: 0 4px 6px -1px rgba(15, 23, 42, .06), 0 20px 50px -12px rgba(15, 23, 42, .18);
    --shadow-btn: 0 4px 14px -2px rgba(99, 102, 241, .45);
    --transition: .2s cubic-bezier(.4, 0, .2, 1);
}

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text-1);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px 16px;
    background: #eef2ff;
}

/* ---- 背景装饰 ---- */
.page-bg {
    position: fixed;
    inset: 0;
    z-index: -1;
    overflow: hidden;
    background: linear-gradient(160deg, #eef2ff 0%, #f5f3ff 45%, #fdf4ff 100%);
}
.page-bg::before,
.page-bg::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    filter: blur(90px);
    opacity: .5;
}
.page-bg::before {
    width: 480px; height: 480px;
    top: -160px; right: -120px;
    background: radial-gradient(circle, #c7d2fe, transparent 70%);
}
.page-bg::after {
    width: 420px; height: 420px;
    bottom: -140px; left: -100px;
    background: radial-gradient(circle, #ddd6fe, transparent 70%);
}

/* ---- 布局 ---- */
.container {
    width: 100%;
    max-width: 480px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* ---- 头部 ---- */
.header { text-align: center; padding: 8px 0 4px; }

.logo {
    width: 56px; height: 56px;
    margin: 0 auto 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    box-shadow: var(--shadow-btn);
    color: #fff;
}
.logo svg { width: 30px; height: 30px; }

.header h1 {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: .5px;
}

.header p {
    margin-top: 6px;
    font-size: 14px;
    color: var(--text-2);
}

/* ---- 卡片 ---- */
.card {
    background: var(--bg-card);
    border: 1px solid rgba(226, 232, 240, .8);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 24px;
}

/* ---- 表单 ---- */
.field { margin-bottom: 20px; }
.field:last-of-type { margin-bottom: 24px; }

.field-head {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

.field-label,
.field-head label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-1);
}

.counter {
    font-size: 12px;
    color: var(--text-3);
    font-variant-numeric: tabular-nums;
    transition: color var(--transition);
}
.counter.near-limit { color: var(--danger); font-weight: 600; }

textarea {
    width: 100%;
    min-height: 108px;
    padding: 12px 14px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 15px;
    font-family: inherit;
    line-height: 1.6;
    color: var(--text-1);
    background: #f8fafc;
    resize: vertical;
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
textarea::placeholder { color: var(--text-3); }
textarea:hover { border-color: #cbd5e1; }
textarea:focus {
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, .12);
}

/* ---- 分段选择器 ---- */
.segmented {
    display: flex;
    gap: 4px;
    padding: 4px;
    margin-top: 8px;
    background: #f1f5f9;
    border-radius: var(--radius-md);
}
.segmented button {
    flex: 1;
    padding: 8px 4px;
    border: none;
    border-radius: var(--radius-sm);
    background: transparent;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-2);
    cursor: pointer;
    transition: background var(--transition), color var(--transition), box-shadow var(--transition);
    white-space: nowrap;
}
.segmented button:hover { color: var(--text-1); }
.segmented button.active {
    background: #fff;
    color: var(--primary-dark);
    font-weight: 600;
    box-shadow: 0 1px 3px rgba(15, 23, 42, .12);
}
.segmented button:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 1px;
}

.options-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

/* ---- 按钮 ---- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 20px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition),
                background var(--transition), opacity var(--transition);
    -webkit-tap-highlight-color: transparent;
}
.btn:active { transform: scale(.97); }
.btn:focus-visible {
    outline: 2px solid var(--primary-dark);
    outline-offset: 2px;
}
.btn:disabled {
    opacity: .65;
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    box-shadow: var(--shadow-btn);
}
.btn-primary:hover:not(:disabled) {
    box-shadow: 0 6px 20px -2px rgba(99, 102, 241, .55);
    transform: translateY(-1px);
}
.btn-primary:active:not(:disabled) { transform: scale(.97); }

.btn-ghost {
    background: #fff;
    color: var(--primary-dark);
    border: 1.5px solid var(--border);
}
.btn-ghost:hover:not(:disabled) {
    border-color: var(--primary-light);
    background: #f5f7ff;
}

.btn-lg { width: 100%; padding: 14px; font-size: 16px; }

/* 按钮加载态 */
.btn-spinner {
    display: none;
    width: 16px; height: 16px;
    border: 2.5px solid rgba(255, 255, 255, .35);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin .7s linear infinite;
}
.btn.loading .btn-spinner { display: inline-block; }

.hint {
    margin-top: 12px;
    text-align: center;
    font-size: 12px;
    color: var(--text-3);
}
.hint kbd {
    padding: 2px 6px;
    border: 1px solid var(--border);
    border-bottom-width: 2px;
    border-radius: 5px;
    background: #f8fafc;
    font-family: inherit;
    font-size: 11px;
}

/* ---- 结果卡片 ---- */
.result-card {
    text-align: center;
    opacity: 0;
    transform: translateY(12px);
    transition: opacity .35s ease, transform .35s ease;
}
.result-card.visible {
    opacity: 1;
    transform: translateY(0);
}
.result-card[hidden] { display: none; }

.qr-frame {
    display: inline-block;
    padding: 16px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: 0 2px 8px rgba(15, 23, 42, .06);
}
.qr-frame img {
    display: block;
    width: 220px;
    height: 220px;
    image-rendering: pixelated;
}

.qr-meta {
    margin-top: 12px;
    font-size: 12px;
    color: var(--text-3);
    font-variant-numeric: tabular-nums;
}

.result-text {
    margin-top: 10px;
    padding: 8px 12px;
    background: #f8fafc;
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--text-2);
    word-break: break-all;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 18px;
}

/* ---- Toast ---- */
.toast-wrap {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: min(90vw, 400px);
    pointer-events: none;
}
.toast {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    background: #fff;
    box-shadow: 0 8px 30px rgba(15, 23, 42, .16);
    font-size: 14px;
    color: var(--text-1);
    opacity: 0;
    transform: translateY(-12px);
    transition: opacity .3s ease, transform .3s ease;
}
.toast.show { opacity: 1; transform: translateY(0); }
.toast::before {
    content: "";
    flex-shrink: 0;
    width: 8px; height: 8px;
    border-radius: 50%;
}
.toast-error::before { background: var(--danger); }
.toast-success::before { background: var(--success); }

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

/* ---- 响应式 ---- */
@media (max-width: 480px) {
    body { padding: 16px 12px; align-items: flex-start; }
    .container { gap: 16px; }
    .header h1 { font-size: 21px; }
    .logo { width: 48px; height: 48px; margin-bottom: 10px; border-radius: 14px; }
    .card { padding: 20px 16px; border-radius: 16px; }
    .options-row { grid-template-columns: 1fr; gap: 12px; }
    .actions { grid-template-columns: 1fr; }
    .qr-frame img { width: 200px; height: 200px; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
    }
}