:root {
 --bg: #f5f7fb;
 --card: #ffffff;
 --main: #2457a6;
 --main-dark: #173f7a;
 --text: #1f2937;
 --muted: #6b7280;
 --border: #d9e1ef;
 --danger: #c62828;
}
* {
 box-sizing: border-box;
}
body {
 margin: 0;
 font-family: "Microsoft YaHei", Arial, sans-serif;
 background: var(--bg);
 color: var(--text);
}
.app {
 width: 1180px;
 max-width: 94%;
 margin: 28px auto;
}
.hero {
 background: linear-gradient(135deg, #1f4e79, #4b8bd6);
 color: #fff;
 border-radius: 18px;
 padding: 30px 36px;
 box-shadow: 0 12px 30px rgba(31, 78, 121, 0.22);
}
.tag {
 margin: 0 0 8px;
 letter-spacing: 1px;
 opacity: 0.9;
}
h1 {
 margin: 0 0 12px;
 font-size: 30px;
}
.intro {
 width: 780px;
 max-width: 100%;
 line-height: 1.8;
 margin: 0;
}
.workspace {
 display: grid;
 grid-template-columns: 430px 1fr;
 gap: 22px;
 margin-top: 22px;
}
.panel {
 background: var(--card);
 border: 1px solid var(--border);
 border-radius: 16px;
 padding: 24px;
 box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}
h2 {
 margin-top: 0;
 color: var(--main-dark);
}
label {
 display: block;
 margin-top: 16px;
 margin-bottom: 7px;
 font-weight: 700;
}
input,
select,
textarea {
 width: 100%;
 border: 1px solid var(--border);
 border-radius: 10px;
 padding: 11px 12px;
 font-size: 15px;
 outline: none;
 background: #fff;
}
input:focus,
select:focus,
textarea:focus {
 border-color: var(--main);
 box-shadow: 0 0 0 3px rgba(36, 87, 166, 0.12);
}
textarea {
 min-height: 140px;
 resize: vertical;
 line-height: 1.6;
}
textarea.small {
 min-height: 88px;
}
.tip {
 margin: 6px 0 0;
 font-size: 13px;
 color: var(--muted);
 line-height: 1.6;
}
.actions {
 display: flex;
 flex-wrap: wrap;
 gap: 10px;
 margin-top: 18px;
}
button {
 border: none;
 border-radius: 10px;
 padding: 11px 16px;
 cursor: pointer;
 font-size: 15px;
 color: #fff;
 background: var(--main);
}
button:hover {
 background: var(--main-dark);
}
button.secondary {
 background: #3f7f5f;
}
button.secondary:hover {
 background: #2f6148;
}
button.ghost,
button.copy {
 background: #eef2f7;
 color: #344054;
}
button.ghost:hover,
button.copy:hover {
 background: #dfe7f1;
}
.loading {
 display: none;
 margin-top: 14px;
 color: var(--main);
 font-weight: 700;
}
.error {
 margin-top: 12px;
 color: var(--danger);
 line-height: 1.7;
 font-weight: 700;
}
.result-title {
 display: flex;
 align-items: center;
 justify-content: space-between;
 gap: 12px;
}
.chat-box {
 min-height: 620px;
 max-height: 720px;
 overflow-y: auto;
 background: #fbfcfe;
 border: 1px solid var(--border);
 border-radius: 14px;
 padding: 16px;
 line-height: 1.8;
 white-space: pre-wrap;
}
.empty {
 color: var(--muted);
 text-align: center;
 margin-top: 200px;
}
.message {
 border-radius: 12px;
 padding: 14px;
 margin-bottom: 14px;
}
.message .role {
 font-weight: 700;
 margin-bottom: 6px;
}
.user-message {
 background: #eaf2ff;
 border: 1px solid #c8dcff;
}
.ai-message {
 background: #ffffff;
 border: 1px solid #e4e7ec;
}
@media (max-width: 900px) {
 .workspace {
 grid-template-columns: 1fr;
 }
 .chat-box {
 min-height: 420px;
 }
}