/* ============ 基础 ============ */
*,
*::before,
*::after { box-sizing: border-box; }

:root {
    --ink: #0f172a;
    --ink-2: #475569;
    --ink-3: #94a3b8;
    --line: rgba(15, 23, 42, .10);
    --card: #ffffff;
    --accent: #4f46e5;
    --accent-2: #7c3aed;
    --radius: 14px;
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06), 0 8px 24px rgba(15, 23, 42, .06);
    --shadow-lg: 0 20px 60px rgba(15, 23, 42, .12);
}

html, body { height: 100%; }

body {
    margin: 0;
    color: var(--ink);
    font: 14px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: #f6f7fb;
    -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

/* ============ 首页背景 ============ */
body.home { overflow-x: hidden; }

.bg-glow {
    position: fixed;
    inset: -20% -10% auto -10%;
    height: 70vh;
    background:
        radial-gradient(560px 340px at 18% 20%, rgba(99, 102, 241, .20), transparent 70%),
        radial-gradient(520px 320px at 78% 8%, rgba(236, 72, 153, .14), transparent 70%),
        radial-gradient(600px 380px at 50% 60%, rgba(14, 165, 233, .12), transparent 70%);
    filter: blur(10px);
    pointer-events: none;
    z-index: 0;
}

/* ============ 顶部 ============ */
.brand {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 22px 32px;
    max-width: 1180px;
    margin: 0 auto;
}

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

.logo-mark {
    width: 26px; height: 26px; border-radius: 9px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    box-shadow: 0 6px 16px rgba(79, 70, 229, .35);
    position: relative;
}
.logo-mark::after {
    content: "";
    position: absolute; inset: 7px;
    border: 2px solid #fff; border-radius: 50%;
    border-right-color: transparent;
    transform: rotate(-30deg);
}

.logo-text { font-weight: 700; letter-spacing: .2px; font-size: 15px; }

.brand-link {
    font-size: 13px;
    color: var(--ink-2);
    text-decoration: none;
    padding: 7px 12px;
    border-radius: 9px;
    border: 1px solid transparent;
    transition: .18s;
}
.brand-link:hover { background: #fff; border-color: var(--line); box-shadow: var(--shadow-sm); }

/* ============ 主区 ============ */
.home-main {
    position: relative;
    z-index: 1;
    max-width: 940px;
    margin: 0 auto;
    padding: 22px 24px 80px;
}

.headline {
    font-size: clamp(26px, 4.4vw, 40px);
    line-height: 1.24;
    letter-spacing: -.6px;
    margin: 26px 0 10px;
    text-align: center;
    font-weight: 800;
    background: linear-gradient(120deg, #0f172a 20%, #4338ca 60%, #7c3aed 90%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subline {
    text-align: center;
    color: var(--ink-2);
    margin: 0 auto 30px;
    max-width: 640px;
    font-size: 13.5px;
    line-height: 1.8;
    text-wrap: balance;
}

/* ============ 搜索框 ============ */
.search-form { display: block; }

.search-box {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 8px 8px 8px 16px;
    box-shadow: var(--shadow-lg);
    transition: .2s;
}
.search-box:focus-within {
    border-color: rgba(79, 70, 229, .45);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, .10), var(--shadow-lg);
}

.search-icon { width: 20px; height: 20px; color: var(--ink-3); flex: none; }

.search-box input {
    flex: 1;
    min-width: 0;
    border: 0;
    outline: 0;
    background: transparent;
    font-size: 16px;
    padding: 12px 4px;
    color: var(--ink);
}
.search-box input::placeholder { color: var(--ink-3); }

.go {
    flex: none;
    border: 0;
    cursor: pointer;
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    padding: 12px 24px;
    border-radius: 13px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    box-shadow: 0 8px 20px rgba(79, 70, 229, .28);
    transition: transform .15s, box-shadow .18s;
}
.go:hover { transform: translateY(-1px); box-shadow: 0 12px 26px rgba(79, 70, 229, .34); }
.go:active { transform: translateY(0) scale(.985); }

/* ============ 引擎选择 ============ */
.picker-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 34px 0 12px;
    gap: 12px;
    flex-wrap: wrap;
}

.picker-title {
    font-weight: 700;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.counter {
    font-weight: 600;
    font-size: 12px;
    color: var(--accent);
    background: rgba(79, 70, 229, .09);
    border-radius: 999px;
    padding: 3px 10px;
}
.counter.full { color: #b45309; background: rgba(217, 119, 6, .12); }

.picker-actions { display: flex; gap: 4px; }

.link-btn {
    border: 0; background: transparent; cursor: pointer;
    font-size: 12.5px; color: var(--ink-2);
    padding: 5px 9px; border-radius: 8px;
}
.link-btn:hover { background: rgba(15, 23, 42, .05); color: var(--ink); }

.picker {
    background: rgba(255, 255, 255, .72);
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 6px 18px 18px;
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(10px);
}

.group { padding-top: 12px; }

.group-name {
    font-size: 11.5px;
    letter-spacing: .06em;
    color: var(--ink-3);
    font-weight: 700;
    margin: 0 0 9px 2px;
    text-transform: uppercase;
}

.chips { display: flex; flex-wrap: wrap; gap: 7px; }

.chip {
    position: relative;
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 7px 12px 7px 10px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: #fff;
    cursor: pointer;
    font-size: 13px;
    color: var(--ink-2);
    transition: .16s;
    user-select: none;
}
.chip:hover { border-color: rgba(79, 70, 229, .35); color: var(--ink); transform: translateY(-1px); }

.chip input { position: absolute; opacity: 0; pointer-events: none; }

.chip-dot {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--c, #64748b);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--c, #64748b) 16%, transparent);
    flex: none;
    transition: .16s;
}

.chip:has(input:checked) {
    border-color: rgba(79, 70, 229, .55);
    background: linear-gradient(180deg, rgba(79, 70, 229, .07), rgba(124, 58, 237, .05));
    color: var(--ink);
    font-weight: 600;
    box-shadow: 0 4px 14px rgba(79, 70, 229, .14);
}

.chip.disabled {
    opacity: .42;
    cursor: not-allowed;
    transform: none;
}

/* ============ 预设 ============ */
.presets {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    margin: 18px 2px 0;
}

.presets-label { font-size: 12px; color: var(--ink-3); }

.preset {
    border: 1px dashed rgba(15, 23, 42, .16);
    background: transparent;
    color: var(--ink-2);
    font-size: 12.5px;
    padding: 6px 12px;
    border-radius: 999px;
    cursor: pointer;
    transition: .16s;
}
.preset:hover {
    border-style: solid;
    border-color: rgba(79, 70, 229, .4);
    color: var(--accent);
    background: rgba(79, 70, 229, .06);
}

/* ============ 布局预览 ============ */
.layout-hint {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 22px 2px 0;
    font-size: 12.5px;
    color: var(--ink-2);
    min-height: 46px;
}

.mini-preview {
    flex: none;
    width: 56px;
    height: 38px;
    display: grid;
    gap: 3px;
    padding: 4px;
    border-radius: 9px;
    background: #eef1f7;
    border: 1px solid var(--line);
    transition: .2s;
}

.mini-preview i { background: #c7cbd8; border-radius: 3px; transition: .2s; }
.mini-preview[data-n="0"] i { display: none; }

.mini-preview[data-n="1"] { grid-template-columns: 1fr; }
.mini-preview[data-n="1"] i:nth-child(n+2) { display: none; }

.mini-preview[data-n="2"] { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr; }
.mini-preview[data-n="2"] i:nth-child(n+3) { display: none; }

.mini-preview[data-n="3"] { grid-template-columns: 1fr 1fr 1fr; grid-template-rows: 1fr; }
.mini-preview[data-n="3"] i:nth-child(n+4) { display: none; }

.mini-preview[data-n="4"] { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }

.mini-preview:not([data-n="0"]) i { background: linear-gradient(135deg, #8b8ff5, #a78bfa); }

.tip {
    margin-top: 26px;
    font-size: 12px;
    line-height: 1.8;
    color: var(--ink-3);
    border-left: 2px solid rgba(79, 70, 229, .25);
    padding-left: 12px;
}

@media (max-width: 640px) {
    .brand { padding: 16px 18px; }
    .home-main { padding: 10px 16px 60px; }
    .headline { margin-top: 14px; }
    .picker { padding: 4px 14px 14px; }
    .search-box { padding: 6px 6px 6px 12px; }
    .search-box input { font-size: 15px; }
    .go { padding: 11px 18px; }
}