/* 通用组件：重置 / 排版 / 按钮 / 表单 / 徽章 / 消息 / toast / 表格 / 导航 */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    min-width: 320px;
    overflow-x: hidden;
    background: var(--surface-alt);
}

body {
    min-width: 320px;
    min-height: 100dvh;
    margin: 0;
    overflow-x: hidden;
    color: var(--ink);
    /* 保持透明，让 ::before 背景图层可见；底色由 html 提供 */
    font-family: var(--font-stack);
    line-height: 1.55;
}

/* 前台招新背景图：固定视口层 + 白色遮罩保证可读性 */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    background:
        var(--bg-veil),
        url("../img/campus-bg.jpg") center 72% / cover no-repeat
            var(--surface-alt);
}

/* 后台页无背景图（依赖 :has；不支持的浏览器退化为显示背景图，无功能影响） */
body:has(main.admin-shell)::before {
    content: none;
}

body > #messages {
    width: min(calc(100% - 2rem), 1180px);
    margin: 0 auto;
}

main {
    width: min(calc(100% - 2rem), 1180px);
    margin: 0 auto;
    padding: 1.5rem 0 3rem;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1,
h2,
h3 {
    color: var(--ink);
    line-height: 1.2;
    font-weight: 800;
    letter-spacing: -0.02em;
}

h1 {
    margin-bottom: 0.5rem;
    font-size: clamp(1.65rem, 3vw, 2.45rem);
}

h2 {
    margin-bottom: 0.6rem;
    font-size: clamp(1.15rem, 2vw, 1.45rem);
}

a {
    color: var(--accent-strong);
    font-weight: 650;
}

button,
input,
select,
textarea {
    min-height: 44px;
    font: inherit;
    border: 1px solid var(--line);
    border-radius: var(--radius-control);
}

/* 默认按钮 = 主 CTA（模板裸 button 即主操作） */
button {
    padding: 0.65rem 1.25rem;
    border: 1px solid rgb(255 255 255 / 0.35);
    color: #ffffff;
    background: var(--dream-gradient);
    cursor: pointer;
    font-weight: 700;
    box-shadow: 0 4px 14px rgb(251 114 153 / 0.28);
    text-shadow: 0 1px 4px rgb(31 36 48 / 0.25);
    transition: transform 120ms ease, box-shadow 120ms ease, filter 120ms ease;
}

/* 后台主按钮保持深饱和品牌渐变（内部工具视觉语言不变） */
.admin-shell button {
    background: var(--brand-gradient);
    text-shadow: none;
}

button:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 8px 20px rgb(251 114 153 / 0.35);
}

button:active:not(:disabled) {
    transform: scale(0.97);
}

button:disabled {
    cursor: not-allowed;
    opacity: 0.55;
    filter: grayscale(0.4);
    box-shadow: none;
}

/* 后台按钮：纯蓝不用渐变 */
.admin-shell button {
    background: var(--brand-blue);
    box-shadow: 0 3px 10px rgb(35 173 229 / 0.25);
}

.admin-shell button:hover:not(:disabled) {
    box-shadow: 0 6px 16px rgb(35 173 229 / 0.3);
}

.admin-shell .btn-secondary {
    border: 1px solid var(--brand-blue);
    color: var(--info-deep);
    background: var(--glass-bg);
    box-shadow: none;
}

.admin-shell .btn-ghost {
    color: var(--brand-blue);
    background: transparent;
    box-shadow: none;
}

.admin-shell .btn-danger {
    color: #ffffff;
    background: var(--danger);
    box-shadow: 0 3px 10px rgb(240 67 90 / 0.25);
}

.btn-secondary {
    border: 1px solid var(--brand-blue);
    color: var(--info-deep);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
    box-shadow: none;
}

.btn-secondary:hover:not(:disabled) {
    background: var(--blue-soft);
}

.btn-ghost {
    color: var(--info-deep);
    background: transparent;
    box-shadow: none;
}

.btn-ghost:hover:not(:disabled) {
    background: var(--glass-bg);
}

.btn-danger {
    background: var(--danger);
    box-shadow: 0 4px 14px rgb(240 67 90 / 0.25);
}

.reset-activity-form .reset-warning {
    color: var(--danger-deep);
    font-weight: 600;
}

.btn-block {
    display: block;
    width: 100%;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 3px solid rgb(35 173 229 / 0.4);
    outline-offset: 3px;
}

input:not([type="radio"]):not([type="checkbox"]),
select,
textarea {
    width: 100%;
    padding: 0.65rem 0.75rem;
    color: var(--ink);
    background: rgb(255 255 255 / 0.66);
    border-color: var(--glass-border-strong);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

input:focus,
select:focus,
textarea:focus {
    border-color: var(--brand-blue);
    box-shadow: 0 0 0 4px rgb(35 173 229 / 0.15);
    outline: none;
}

input[type="radio"] {
    width: 1.1rem;
    min-height: 1.1rem;
    accent-color: var(--brand-blue);
}

label {
    display: block;
    color: var(--muted);
    font-weight: 650;
}

form {
    display: grid;
    gap: 0.75rem;
}

form > button {
    justify-self: start;
}

/* 服务端 flash 消息：左侧色条玻璃卡片 */
.message {
    margin: 1rem 0 0;
    padding: 0.75rem 1rem;
    border: 1px solid var(--glass-border);
    border-left: 4px solid var(--warning);
    border-radius: var(--radius-control);
    color: var(--ink);
    background: var(--glass-bg-strong);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    box-shadow: var(--glass-shadow);
}

/* 状态徽章（前后台共用） */
.badge {
    display: inline-flex;
    align-items: center;
    min-height: 1.6rem;
    padding: 0.1rem 0.7rem;
    border-radius: var(--radius-pill);
    font-size: 0.82rem;
    font-weight: 700;
    white-space: nowrap;
}

.badge-warning {
    color: #a15c07;
    background: rgb(255 159 67 / 0.16);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

.badge-success {
    color: #0f7a4e;
    background: rgb(35 196 131 / 0.16);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

.badge-danger {
    color: #c22743;
    background: rgb(240 67 90 / 0.14);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

.badge-info {
    color: var(--info-deep);
    background: rgb(35 173 229 / 0.14);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

.badge-muted {
    color: var(--muted);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
}

/* toast 浮层（ui.js 挂载） */
#toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1200;
    display: grid;
    gap: 0.5rem;
    width: min(calc(100vw - 2rem), 22rem);
    pointer-events: none;
}

.toast {
    padding: 0.75rem 1rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-control);
    color: var(--ink);
    background: var(--glass-bg-strong);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    box-shadow: var(--shadow-lift);
    opacity: 0;
    transform: translateY(-6px);
    transition: opacity 200ms ease, transform 200ms ease;
}

.toast-visible {
    opacity: 1;
    transform: translateY(0);
}

.toast-success {
    color: var(--success-deep);
    background: rgb(35 196 131 / 0.2);
}

.toast-error {
    color: var(--danger-deep);
    background: rgb(240 67 90 / 0.16);
}

.toast-info {
    color: var(--info-deep);
    background: rgb(35 173 229 / 0.18);
}

table {
    width: 100%;
    border-collapse: collapse;
    background: transparent;
}

th,
td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--line);
    text-align: left;
    vertical-align: top;
}

th {
    color: var(--muted);
    font-size: 0.9rem;
    white-space: nowrap;
}

tbody tr:nth-child(even) {
    background: rgb(247 249 252 / 0.5);
}

tbody tr:hover {
    background: rgb(255 240 245 / 0.65);
}

/* 前台分页面导航：胶囊 */
#activity-navigation {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
}

/* 答题日期入口：不可用与可答分两组；窄屏两组各竖排成列、顶部对齐，宽屏组内横排成一行 */
.quiz-day-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: flex-start;
    gap: 0.65rem;
}

.quiz-day-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.65rem;
}

@media (min-width: 960px) {
    .quiz-day-group {
        flex-direction: row;
    }
}

#activity-navigation a,
.quiz-day-links .quiz-day-link {
    display: inline-flex;
    justify-content: center;
    min-height: 44px;
    align-items: center;
    padding: 0.55rem 1rem;
    border: 1px solid var(--glass-border-strong);
    border-radius: var(--radius-pill);
    color: var(--info-deep);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur-light);
    -webkit-backdrop-filter: var(--glass-blur-light);
    text-decoration: none;
    transition: transform 120ms ease, background 120ms ease;
}

#activity-navigation a:hover,
.quiz-day-links a.quiz-day-link:hover {
    transform: translateY(-1px);
}

/* 已错过 / 已做过的答题日：整体变灰且不可点击 */
.quiz-day-links span.quiz-day-disabled {
    color: #8a8f98;
    background: rgb(138 143 152 / 0.16);
    border-color: rgb(138 143 152 / 0.35);
    cursor: not-allowed;
    filter: grayscale(1);
    opacity: 0.8;
    box-shadow: none;
    user-select: none;
}

.quiz-day-links .quiz-day-state {
    margin-left: 0.45rem;
    padding: 0.1rem 0.5rem;
    border-radius: var(--radius-pill);
    font-style: normal;
    font-size: 0.78em;
    color: #8a8f98;
    background: rgb(138 143 152 / 0.18);
}

#activity-navigation a[aria-current="page"] {
    color: #ffffff;
    background: var(--dream-gradient);
    box-shadow: 0 4px 12px rgb(251 114 153 / 0.3);
    text-shadow: 0 1px 4px rgb(31 36 48 / 0.25);
}

[hidden] {
    display: none !important;
}

/* 页面淡入（ui.js 添加 .page-fade-in） */
.page-fade-in {
    animation: page-fade 200ms ease-out;
}

@keyframes page-fade {
    from {
        opacity: 0;
        transform: translateY(6px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}