/* ===== 全局重置 & 基础 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 品牌色：淘宝橙（ChatUI 品牌主色） */
    --primary: #FF6200;
    --primary-dark: #D45A00;
    --secondary: #FFA040;
    --accent: #F59E0B;
    --success: #22C55E;
    --danger: #EF4444;
    /* 背景与文字：夜青黑 + 雾灰蓝（ChatUI 语义色） */
    --bg: #F3F6F8;
    --white: #FFFFFF;
    --text-dark: #11192D;
    --text-mid: #4A5675;
    --text-light: #8C9AB5;
    --border: #E2E8F0;
    --border-light: #F1F5F9;
    --radius: 12px;
    --radius-sm: 8px;
    --radius-btn: 9999px;
    /* 中性阴影：夜青黑基色 */
    --shadow: 0 4px 24px rgba(17, 25, 45, 0.08);
    --shadow-lg: 0 12px 48px rgba(17, 25, 45, 0.12);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html,
body {
    height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text-dark);
    line-height: 1.6;
    height: 100vh;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: min(100%, 1920px);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 导航栏 ===== */
.navbar {
    flex-shrink: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 98, 0, 0.06);
}

.navbar .container {
    max-width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.nav-logo .logo-group {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0px;
}

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

.nav-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}

.nav-logo .brand-name {
    font-weight: 800;
    font-size: 22px;
    color: var(--text-dark);
    letter-spacing: -0.5px;
    white-space: nowrap;
}

.nav-logo .brand-name .highlight {
    color: var(--primary);
}

.nav-logo .brand-sub {
    font-size: 11px;
    font-weight: 500;
    color: var(--text-light);
    letter-spacing: 0.3px;
    margin-left: 46px;
    padding-top: 1px;
    white-space: nowrap;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-link {
    font-family: inherit;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-mid);
    text-decoration: none;
    padding: 8px 16px;
    border: none;
    background: transparent;
    border-radius: var(--radius-btn);
    cursor: pointer;
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--primary);
    background: rgba(255, 98, 0, 0.06);
}

/* 功能入口按钮 */
.nav-actions .btn-nav-coming {
    position: relative;
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    color: var(--primary);
    padding: 7px 14px;
    border: 1px dashed rgba(255, 98, 0, 0.35);
    border-radius: var(--radius-btn);
    background: rgba(255, 98, 0, 0.04);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.nav-actions .btn-nav-coming:hover {
    background: rgba(255, 98, 0, 0.10);
    border-color: var(--primary);
}

/* 当前页高亮 */
.nav-actions .btn-nav-coming.btn-highlight {
    color: white;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border: 1px solid transparent;
    box-shadow: 0 4px 16px rgba(255, 98, 0, 0.30);
}

.nav-actions .btn-nav-coming.btn-highlight:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(255, 98, 0, 0.40);
    background: linear-gradient(135deg, var(--primary), var(--secondary));
}

/* ===== 主体 ===== */
.exam-main {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    padding: 24px 0 40px;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.exam-main.ready {
    opacity: 1;
}

/* ===== 页面标题 ===== */
.page-header {
    display: flex;
    align-items: baseline;
    gap: 12px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.page-header h1 {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -0.5px;
    margin: 0;
}

.page-header .page-subtitle {
    font-size: 13px;
    color: var(--text-mid);
}

/* ===== 网格布局 ===== */
.exam-grid {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 20px;
    align-items: stretch;
}

/* ===== 通用卡片 ===== */
.exam-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px 24px;
    border: 1px solid rgba(255, 98, 0, 0.06);
}

.exam-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 14px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.exam-card-header h2 {
    font-size: 15px;
    font-weight: 700;
}

/* ===== 表单区 ===== */
.input-card {
    display: flex;
    flex-direction: column;
}

.form-group {
    margin-bottom: 18px;
}

.form-group:last-child {
    margin-bottom: 0;
}

.form-label {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin-bottom: 10px;
}

.form-label .label-text {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-dark);
}

.form-label .label-hint {
    font-size: 12px;
    color: var(--text-light);
}

/* 年级选项卡片 */
.grade-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.grade-option {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 10px 8px;
    background: var(--bg);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    font-family: inherit;
    transition: var(--transition);
}

.grade-option:hover {
    border-color: var(--primary);
    background: rgba(255, 98, 0, 0.04);
}

.grade-option.active {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(255, 98, 0, 0.08), rgba(255, 160, 64, 0.08));
    box-shadow: 0 4px 12px rgba(255, 98, 0, 0.15);
}

.grade-option .grade-name {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-dark);
}

.grade-option.active .grade-name {
    color: var(--primary);
}

.grade-option .grade-desc {
    font-size: 11px;
    color: var(--text-light);
}

.grade-option.active .grade-desc {
    color: var(--primary-dark);
}

/* 主题输入框 */
.input-wrapper {
    position: relative;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--white);
    transition: var(--transition);
    overflow: hidden;
}

.input-wrapper:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(255, 98, 0, 0.1);
}

.input-wrapper input {
    width: 100%;
    padding: 14px 16px;
    border: none;
    outline: none;
    font-family: inherit;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-dark);
    background: transparent;
}

.input-wrapper input::placeholder {
    color: var(--text-light);
}

.text-status {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 8px;
    font-size: 12px;
    color: var(--text-light);
}

.char-count strong {
    color: var(--text-mid);
    font-weight: 600;
}

.tool-btn-inline {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    font-weight: 500;
    color: var(--text-mid);
    background: transparent;
    border: none;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    transition: var(--transition);
}

.tool-btn-inline:hover {
    color: var(--danger);
    background: rgba(239, 68, 68, 0.06);
}

/* 推荐主题区域 */
.topic-suggest {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.topic-chip {
    font-family: inherit;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-mid);
    background: var(--bg);
    border: 1px solid var(--border);
    padding: 6px 14px;
    border-radius: var(--radius-btn);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.topic-chip:hover {
    color: var(--primary);
    border-color: var(--primary);
    background: rgba(255, 98, 0, 0.06);
}

.topic-chip.active {
    color: white;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-color: transparent;
    box-shadow: 0 2px 8px rgba(255, 98, 0, 0.25);
}

/* 校验提示 */
.validation-alert {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 12px;
    padding: 10px 14px;
    background: rgba(239, 68, 68, 0.06);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--danger);
}

.validation-alert[hidden] {
    display: none;
}

.alert-icon {
    flex-shrink: 0;
}

/* ===== 右侧设置面板 ===== */
.settings-panel {
    display: flex;
}

.settings-card {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.settings-section {
    padding: 4px 0;
}

.settings-section-header {
    margin-bottom: 12px;
}

.settings-section-header h2 {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-dark);
}

.settings-divider {
    height: 1px;
    background: var(--border);
    margin: 16px 0;
}

.setting-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
}

.setting-icon {
    font-size: 16px;
    flex-shrink: 0;
}

.setting-info {
    flex: 1;
    min-width: 0;
}

.setting-label {
    font-size: 12px;
    color: var(--text-light);
    margin-bottom: 2px;
}

.setting-value {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-dark);
}

.tips-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.tips-list li {
    position: relative;
    padding-left: 16px;
    margin-bottom: 6px;
    font-size: 12px;
    color: var(--text-mid);
    line-height: 1.5;
}

.tips-list li::before {
    content: '•';
    position: absolute;
    left: 4px;
    color: var(--primary);
    font-weight: bold;
}

/* ===== 操作栏 ===== */
.action-bar {
    margin-top: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.action-info {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 20px;
    background: linear-gradient(135deg, rgba(255, 98, 0, 0.04), rgba(255, 160, 64, 0.04));
    border: 1px solid rgba(255, 98, 0, 0.12);
    border-radius: var(--radius);
    flex: 1;
}

.action-info .info-icon {
    font-size: 16px;
}

.action-info .info-text {
    font-size: 13px;
    color: var(--text-mid);
}

.action-info.generating {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.06), rgba(245, 158, 11, 0.1));
    border-color: rgba(245, 158, 11, 0.25);
}

.action-info.generating .info-text {
    color: #B45309;
}

.btn-generate {
    padding: 14px 40px;
    font-size: 15px;
    font-weight: 700;
    font-family: inherit;
    color: white;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border: none;
    border-radius: var(--radius-btn);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 8px 24px rgba(255, 98, 0, 0.30);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    white-space: nowrap;
}

.btn-generate:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(255, 98, 0, 0.40);
}

.btn-generate:active:not(:disabled) {
    transform: translateY(0);
}

.btn-generate:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}

.btn-generate.loading {
    pointer-events: none;
}

.btn-generate.loading .btn-text {
    display: none;
}

.btn-generate.loading .btn-loading {
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-generate.loading .btn-loading::before {
    content: '';
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

/* ===== 结果区 ===== */
.result-card {
    margin-top: 20px;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-card[hidden] {
    display: none;
}

.result-toolbar {
    display: flex;
    gap: 8px;
}

.tool-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-mid);
    background: var(--bg);
    border: 1px solid var(--border);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    transition: var(--transition);
    text-decoration: none;
}

/* 禁用态：AI回复未结束前置灰不可点 */
.tool-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.tool-btn:hover {
    color: var(--primary);
    border-color: var(--primary);
    background: rgba(255, 98, 0, 0.04);
}

.result-body {
    min-height: 100px;
}

/* 流式输出状态指示 */
.stream-status {
    display: flex;
    align-items: center;
    padding: 10px 14px;
    margin-bottom: 12px;
    background: linear-gradient(135deg, rgba(255, 98, 0, 0.04), rgba(255, 160, 64, 0.04));
    border: 1px solid rgba(255, 98, 0, 0.12);
    border-radius: var(--radius-sm);
}

.stream-status[hidden] {
    display: none;
}

.stream-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
}

.stream-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--primary);
    animation: pulse 1.2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.4;
        transform: scale(0.8);
    }
}

.stream-text {
    font-size: 13px;
    font-weight: 500;
    color: var(--primary);
}

/* ===== Markdown 渲染样式 ===== */
.markdown-body {
    font-size: 14px;
    line-height: 1.8;
    color: var(--text-dark);
    word-wrap: break-word;
}

.markdown-body:empty {
    display: none;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
    margin-top: 24px;
    margin-bottom: 12px;
    font-weight: 700;
    color: var(--text-dark);
}

.markdown-body h1 {
    font-size: 20px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--primary);
    color: var(--primary);
}

.markdown-body h2 {
    font-size: 17px;
    padding-bottom: 6px;
    border-bottom: 1px solid var(--border);
}

.markdown-body h3 {
    font-size: 15px;
    color: var(--primary-dark);
}

.markdown-body h4 {
    font-size: 14px;
}

.markdown-body p {
    margin: 8px 0;
}

.markdown-body ul,
.markdown-body ol {
    margin: 8px 0;
    padding-left: 24px;
}

.markdown-body li {
    margin: 4px 0;
}

.markdown-body strong {
    font-weight: 700;
    color: var(--text-dark);
}

.markdown-body em {
    font-style: italic;
}

.markdown-body code {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 13px;
    background: var(--border-light);
    color: var(--primary-dark);
    padding: 2px 6px;
    border-radius: 4px;
}

.markdown-body pre {
    background: #1E293B;
    color: #E2E8F0;
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 12px 0;
}

.markdown-body pre code {
    background: transparent;
    color: inherit;
    padding: 0;
}

.markdown-body blockquote {
    margin: 12px 0;
    padding: 10px 16px;
    border-left: 4px solid var(--primary);
    background: rgba(255, 98, 0, 0.04);
    color: var(--text-mid);
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0;
    font-size: 13px;
}

.markdown-body th,
.markdown-body td {
    border: 1px solid var(--border);
    padding: 8px 12px;
    text-align: left;
}

.markdown-body th {
    background: var(--bg);
    font-weight: 700;
    color: var(--text-dark);
}

.markdown-body tr:nth-child(even) td {
    background: rgba(241, 245, 249, 0.5);
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 20px 0;
}

.markdown-body a {
    color: var(--primary);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

/* ===== 响应式 ===== */
@media (max-width: 960px) {
    .exam-grid {
        grid-template-columns: 1fr;
    }

    .settings-panel {
        order: -1;
    }

    .grade-options {
        grid-template-columns: repeat(3, 1fr);
    }

    .action-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .btn-generate {
        width: 100%;
    }

    .nav-logo .brand-sub {
        display: none;
    }
}

@media (max-width: 600px) {
    .container {
        padding: 0 16px;
    }

    .nav-actions {
        gap: 6px;
    }

    .nav-actions .btn-nav-coming,
    .nav-link {
        padding: 6px 10px;
        font-size: 12px;
    }

    .page-header h1 {
        font-size: 20px;
    }

    .grade-options {
        grid-template-columns: 1fr;
    }
}