:root {
    --paper: #f3eee4;
    --paper-2: #e8e0d2;
    --ink: #1a1714;
    --ink-soft: #5c5348;
    --line: #d4cbb8;
    --forest: #2c4a3e;
    --forest-2: #3d6a58;
    --copper: #b4532a;
    --white: #fcfaf6;
    --shadow: 0 18px 40px rgba(26, 23, 20, 0.08);
    --radius: 18px;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
    font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "Georgia", serif;
    background:
        radial-gradient(1200px 500px at 10% -10%, rgba(44, 74, 62, 0.08), transparent 50%),
        var(--paper);
    color: var(--ink);
}

a { color: var(--forest); }
button, input, textarea { font-family: "IBM Plex Sans", "PingFang SC", "Microsoft YaHei", sans-serif; }

.app-shell {
    max-width: 1080px;
    margin: 0 auto;
    padding: 28px 20px 48px;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 22px;
}
.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}
.mark {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: var(--forest);
    color: var(--white);
    display: grid;
    place-items: center;
    font-weight: 700;
    letter-spacing: 0.04em;
}
.brand h1 {
    margin: 0;
    font-size: 22px;
    letter-spacing: 0.06em;
}
.brand p {
    margin: 2px 0 0;
    color: var(--ink-soft);
    font-size: 13px;
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
}
.nav-link {
    color: var(--ink-soft);
    text-decoration: none;
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
    font-size: 14px;
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: var(--white);
}
.nav-link:hover { color: var(--forest); border-color: var(--forest-2); }

.panel {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.chat-board { min-height: 62vh; display: flex; flex-direction: column; }
.messages {
    flex: 1;
    padding: 22px 22px 8px;
    overflow-y: auto;
    max-height: calc(100vh - 260px);
}
.msg {
    max-width: 82%;
    margin: 0 0 16px;
    padding: 14px 16px;
    border-radius: 16px;
    line-height: 1.7;
    font-size: 15px;
    white-space: pre-wrap;
    word-break: break-word;
}
.msg.user {
    margin-left: auto;
    background: var(--forest);
    color: var(--white);
    border-bottom-right-radius: 6px;
}
.msg.assistant {
    background: #f6f1e7;
    border: 1px solid var(--line);
    border-bottom-left-radius: 6px;
}
.msg .role {
    font-size: 12px;
    opacity: 0.7;
    margin-bottom: 6px;
    font-family: "IBM Plex Sans", sans-serif;
}
.msg .status {
    font-size: 12px;
    color: var(--ink-soft);
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
    margin-bottom: 8px;
}
.think-anim {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 2px 0 10px;
    min-height: 28px;
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
    color: var(--forest);
}
.think-anim[hidden] { display: none; }
.think-dots {
    display: inline-flex;
    align-items: center;
    gap: 5px;
}
.think-dots i {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--forest);
    opacity: 0.35;
    animation: think-bounce 1.05s ease-in-out infinite;
}
.think-dots i:nth-child(2) { animation-delay: 0.15s; }
.think-dots i:nth-child(3) { animation-delay: 0.3s; }
.think-label {
    font-size: 13px;
    letter-spacing: 0.02em;
}
.think-label::after {
    content: "";
    animation: think-ellipsis 1.4s steps(4, end) infinite;
}
@keyframes think-bounce {
    0%, 80%, 100% { transform: translateY(0); opacity: 0.3; }
    40% { transform: translateY(-5px); opacity: 1; }
}
@keyframes think-ellipsis {
    0% { content: ""; }
    25% { content: "."; }
    50% { content: ".."; }
    75% { content: "..."; }
}
.thinking {
    margin: 0 0 10px;
    padding: 8px 10px;
    border-radius: 10px;
    background: rgba(44, 74, 62, 0.05);
    color: var(--ink-soft);
}
.thinking summary {
    cursor: pointer;
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
    font-size: 12px;
    user-select: none;
}
.thinking-body {
    margin-top: 6px;
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 13px;
    line-height: 1.65;
    opacity: 0.9;
}
.answer { white-space: pre-wrap; word-break: break-word; }
.answer.streaming::after {
    content: "▍";
    margin-left: 2px;
    color: var(--forest);
    animation: blink 1s step-end infinite;
}
@keyframes blink {
    50% { opacity: 0; }
}
.sources {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 10px;
}
.source-chip {
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
    font-size: 12px;
    background: var(--white);
    border: 1px dashed var(--copper);
    color: var(--copper);
    border-radius: 999px;
    padding: 3px 10px;
}
.channel-notice {
    margin-top: 14px;
    padding-top: 12px;
    border-top: 1px solid var(--line);
    font-size: 12px;
    font-weight: 700;
    line-height: 1.7;
    color: var(--ink-soft);
    white-space: pre-wrap;
    word-break: break-word;
}
.empty-hint {
    text-align: center;
    color: var(--ink-soft);
    padding: 72px 16px;
    font-size: 15px;
}

.composer {
    display: flex;
    gap: 10px;
    padding: 16px;
    border-top: 1px solid var(--line);
}
.composer textarea {
    flex: 1;
    resize: none;
    min-height: 56px;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 12px 14px;
    background: var(--paper);
    color: var(--ink);
    outline: none;
}
.composer textarea:focus { border-color: var(--forest-2); }
.btn {
    border: 0;
    border-radius: 12px;
    padding: 0 18px;
    background: var(--forest);
    color: var(--white);
    cursor: pointer;
    font-size: 14px;
}
.btn:disabled { opacity: 0.55; cursor: not-allowed; }
.btn.ghost {
    background: transparent;
    color: var(--ink-soft);
    border: 1px solid var(--line);
}
.btn.danger { background: var(--copper); }

.kb-grid { display: grid; gap: 18px; }
.upload-box {
    padding: 28px 22px;
    text-align: center;
    border: 1.5px dashed var(--forest-2);
    border-radius: var(--radius);
    background: rgba(44, 74, 62, 0.04);
    font-family: "IBM Plex Sans", "PingFang SC", sans-serif;
}
.upload-box strong { display: block; margin: 8px 0 4px; font-size: 16px; }
.upload-box span { color: var(--ink-soft); font-size: 13px; }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-family: "IBM Plex Sans", "PingFang SC", sans-serif; font-size: 14px; }
th, td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); }
th { color: var(--ink-soft); font-weight: 600; background: #f7f3ea; }
.tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 12px;
}
.tag.ok { background: #e4efe8; color: var(--forest); }
.tag.wait { background: #efe8d8; color: #8a6a24; }
.tag.fail { background: #f8e6df; color: var(--copper); }

.login-card {
    max-width: 420px;
    margin: 48px auto;
    padding: 28px;
}
.login-card h2 { margin: 0 0 8px; }
.login-card p { margin: 0 0 18px; color: var(--ink-soft); font-family: "IBM Plex Sans", sans-serif; font-size: 14px; }
.login-card input {
    width: 100%;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 0 12px;
    margin-bottom: 12px;
    background: var(--paper);
}
.err { color: var(--copper); font-size: 13px; font-family: "IBM Plex Sans", sans-serif; min-height: 18px; }

@media (max-width: 720px) {
    .msg { max-width: 94%; }
    .brand h1 { font-size: 18px; }
}