:root {
    --bg: #f7f7f5;
    --surface: #ffffff;
    --text: #1f1f1f;
    --muted: #777777;
    --accent: #e44332;
    --border: #e7e7e5;
    --hover: #f0f0ee;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #121212;
        --surface: #1c1c1c;
        --text: #eeeeee;
        --muted: #9a9a9a;
        --accent: #e44332;
        --border: #2c2c2c;
        --hover: #262626;
    }
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    height: 100%;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    -webkit-font-smoothing: antialiased;
}

#app {
    display: flex;
    height: 100dvh;
    overflow: hidden;
}

/* ---------- 侧边栏 ---------- */

.sidebar {
    width: 250px;
    flex: 0 0 250px;
    display: flex;
    flex-direction: column;
    padding: 18px 12px;
    border-right: 1px solid var(--border);
    background: var(--surface);
}

.brand {
    padding: 0 8px 18px;
    font-size: 20px;
    font-weight: 800;
    color: var(--accent);
    letter-spacing: 0.5px;
}

.nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
    overflow-y: auto;
    flex: 1;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    padding: 10px 10px;
    border: 0;
    border-radius: 9px;
    background: transparent;
    color: var(--text);
    font-size: 14px;
    text-align: left;
    cursor: pointer;
}

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

.nav-btn.active {
    background: color-mix(in srgb, var(--accent) 13%, transparent);
    color: var(--accent);
    font-weight: 600;
}

.nav-label {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.count {
    font-size: 12px;
    color: var(--muted);
}

.nav-btn.active .count {
    color: var(--accent);
}

.sidebar-footer {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding-top: 10px;
    border-top: 1px solid var(--border);
}

.ghost-btn {
    border: 0;
    background: transparent;
    color: var(--muted);
    text-align: left;
    padding: 9px 10px;
    border-radius: 9px;
    font-size: 13px;
    cursor: pointer;
}

.ghost-btn:hover {
    background: var(--hover);
    color: var(--text);
}

/* ---------- 主区域 ---------- */

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.topbar {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 14px 18px 6px;
}

.topbar h1 {
    flex: 1;
    margin: 0;
    font-size: 21px;
    font-weight: 700;
}

.icon-btn {
    border: 0;
    background: transparent;
    color: var(--muted);
    font-size: 20px;
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
}

.icon-btn:hover {
    background: var(--hover);
    color: var(--text);
}

#menu {
    display: none;
}

.quick-add {
    display: flex;
    gap: 8px;
    padding: 8px 18px 14px;
}

.quick-add input {
    flex: 1;
    min-width: 0;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--surface);
    color: var(--text);
    font-size: 15px;
    outline: none;
}

.quick-add input:focus {
    border-color: var(--accent);
}

.quick-add button {
    padding: 0 20px;
    border: 0;
    border-radius: 10px;
    background: var(--accent);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
}

.quick-add button:hover {
    filter: brightness(1.05);
}

.banner {
    margin: 0 18px 12px;
    padding: 10px 12px;
    border-radius: 9px;
    background: #fdecea;
    color: #b71c1c;
    font-size: 13px;
}

@media (prefers-color-scheme: dark) {
    .banner {
        background: #3a1c1a;
        color: #ffb4ab;
    }
}

.task-list {
    flex: 1;
    overflow-y: auto;
    padding: 0 18px 32px;
}

.task {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 11px 8px;
    border-bottom: 1px solid var(--border);
}

.task:hover {
    background: var(--hover);
    border-radius: 8px;
}

.task input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--accent);
    flex: 0 0 auto;
    cursor: pointer;
}

.content {
    flex: 1;
    min-width: 0;
}

.content .title {
    font-size: 15px;
    line-height: 1.35;
    word-break: break-word;
}

.meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 3px;
    font-size: 12px;
    color: var(--muted);
}

.meta .overdue {
    color: #e53935;
}

.meta .today {
    color: #fb8c00;
}

.prio {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex: 0 0 auto;
}

.delete-btn {
    border: 0;
    background: transparent;
    color: var(--muted);
    font-size: 15px;
    padding: 6px 8px;
    border-radius: 7px;
    cursor: pointer;
    opacity: 0;
}

.task:hover .delete-btn,
.task:focus-within .delete-btn {
    opacity: 1;
}

.delete-btn:hover {
    background: #fdecea;
    color: #b71c1c;
}

.empty {
    padding: 64px 24px;
    text-align: center;
    color: var(--muted);
    font-size: 14px;
}

.hidden {
    display: none !important;
}

/* ---------- 弹窗与提示 ---------- */

dialog {
    width: min(420px, 90vw);
    border: 0;
    border-radius: 14px;
    padding: 22px;
    background: var(--surface);
    color: var(--text);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

dialog::backdrop {
    background: rgba(0, 0, 0, 0.5);
}

dialog h2 {
    margin: 0 0 10px;
    font-size: 18px;
}

dialog .hint {
    margin: 0 0 14px;
    color: var(--muted);
    font-size: 13px;
    line-height: 1.5;
}

dialog label {
    display: block;
    font-size: 13px;
    color: var(--muted);
    margin-bottom: 6px;
}

dialog input {
    width: 100%;
    padding: 11px 12px;
    border: 1px solid var(--border);
    border-radius: 9px;
    background: var(--bg);
    color: var(--text);
    font-size: 14px;
    outline: none;
}

dialog input:focus {
    border-color: var(--accent);
}

dialog .row {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    margin-top: 20px;
}

dialog button {
    padding: 9px 16px;
    border: 1px solid var(--border);
    border-radius: 9px;
    background: var(--surface);
    color: var(--text);
    font-size: 14px;
    cursor: pointer;
}

dialog button.primary {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

#toast {
    position: fixed;
    left: 50%;
    bottom: 28px;
    transform: translateX(-50%) translateY(16px);
    background: #323232;
    color: #fff;
    padding: 10px 16px;
    border-radius: 9px;
    font-size: 14px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.18s ease, transform 0.18s ease;
    max-width: 80vw;
    text-align: center;
}

#toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

#backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 9;
}

/* ---------- 移动端 ---------- */

@media (max-width: 760px) {
    .sidebar {
        position: fixed;
        inset: 0 auto 0 0;
        z-index: 10;
        transform: translateX(-100%);
        transition: transform 0.2s ease;
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.2);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    #backdrop.show {
        display: block;
    }

    #menu {
        display: inline-block;
    }

    .topbar {
        padding: 12px 12px 4px;
    }

    .quick-add {
        padding: 8px 12px 12px;
    }

    .task-list {
        padding: 0 12px 24px;
    }

    .banner {
        margin: 0 12px 10px;
    }

    .delete-btn {
        opacity: 1;
    }
}