/* ===================================
   主题配色系统（统一入口）
   只改这里 = 全站换肤
=================================== */

:root {
    /* 品牌主色 */
    --color-primary: #3b82f6;
    --color-primary-hover: #2563eb;
    --color-accent: #60a5fa;

    /* 状态色 */
    --color-error: #ef4444;
    --color-success: #22c55e;

    /* 暗主题 */
    --dark-bg-main: #0b1020;
    --dark-bg-card: rgba(18, 25, 45, 0.88);
    --dark-bg-input: rgba(255,255,255,0.08);
    --dark-text-main: #e5e7eb;
    --dark-text-muted: #9ca3af;
    --dark-border: rgba(255,255,255,0.18);

    /* 亮主题 */
    --light-bg-main: #f4f6fa;
    --light-bg-card: rgba(255,255,255,0.96);
    --light-bg-input: #ffffff;
    --light-text-main: #111827;
    --light-text-muted: #6b7280;
    --light-border: rgba(209,213,219,0.8);

    /* 阴影 */
    --shadow-card: 0 20px 50px rgba(0,0,0,0.25);
}

/* -----------------------------------
   全局基础样式
----------------------------------- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    transition: background-color 0.4s, color 0.4s;
}

/* 背景容器 */
#background {
    position: fixed;
    inset: 0;
    z-index: -1;
}

#background,
#background canvas {
    pointer-events: none;
}

/* -----------------------------------
   登录容器
----------------------------------- */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
}

/* 登录卡片 */
.login-card {
    width: 360px;
    padding: 40px 35px;
    border-radius: 16px;
    box-shadow: var(--shadow-card);
    text-align: center;
    backdrop-filter: blur(15px);
    transition: background 0.4s, color 0.4s;
}

/* 标题 */
.login-card h1 {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 30px;
}

/* 输入组 */
.input-group {
    margin-bottom: 20px;
    text-align: left;
}

.input-group label {
    font-size: 14px;
    margin-bottom: 5px;
    display: block;
    color: var(--dark-text-muted);
}

/* 输入框 */
.input-group input {
    width: 100%;
    padding: 12px 15px;
    border-radius: 8px;
    font-size: 14px;
    outline: none;
    transition: background 0.4s, color 0.4s, border 0.4s;
}

/* 登录按钮 / 通用按钮 */
button {
    width: 100%;
    padding: 13px 0;
    border: none;
    border-radius: 10px;
    background: var(--color-primary);
    color: #fff;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
}

button:hover {
    background: var(--color-primary-hover);
    transform: translateY(-2px);
}

/* 错误提示 */
.error-msg {
    font-size: 13px;
    min-height: 18px;
    margin-bottom: 10px;
    color: var(--color-error);
    text-align: left;
}

/* -----------------------------------
   主题切换按钮
----------------------------------- */
.theme-toggle-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10;
}

.theme-toggle {
    padding: 10px 18px;
    min-width: 90px;
    border-radius: 8px;
    background: var(--color-primary);
    color: #fff;
    font-weight: 600;
    font-size: 14px;
    white-space: nowrap;
}

.theme-toggle:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
}

/* -----------------------------------
   亮暗主题
----------------------------------- */

/* 暗主题 */
body.dark {
    background-color: var(--dark-bg-main);
    color: var(--dark-text-main);
}

body.dark .login-card,
body.dark .notfound-card {
    background: var(--dark-bg-card);
    color: var(--dark-text-main);
}

body.dark input {
    background: var(--dark-bg-input);
    color: var(--dark-text-main);
    border: 1px solid var(--dark-border);
}

/* 亮主题 */
body.light {
    background-color: var(--light-bg-main);
    color: var(--light-text-main);
}

body.light .login-card,
body.light .notfound-card {
    background: var(--light-bg-card);
    color: var(--light-text-main);
}

body.light input {
    background: var(--light-bg-input);
    color: var(--light-text-main);
    border: 1px solid var(--light-border);
}

/* ===================================
   404 页面
=================================== */

.notfound-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
}

.notfound-card {
    width: 420px;
    padding: 50px 40px;
    border-radius: 18px;
    text-align: center;
    backdrop-filter: blur(16px);
    box-shadow: var(--shadow-card);
    transition: background 0.4s, color 0.4s;
}

.error-code {
    font-size: 96px;
    font-weight: 700;
    letter-spacing: 6px;
    color: var(--color-primary);
    animation: float404 4s ease-in-out infinite;
}

.error-line {
    width: 60px;
    height: 4px;
    margin: 20px auto;
    border-radius: 4px;
    background: linear-gradient(
        90deg,
        var(--color-primary),
        var(--color-accent)
    );
}

.notfound-card h2 {
    font-size: 22px;
    margin-bottom: 12px;
}

.notfound-card p {
    font-size: 14px;
    color: var(--dark-text-muted);
    line-height: 1.6;
    margin-bottom: 30px;
}

/* 404 动画 */
@keyframes float404 {
    0% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
    100% { transform: translateY(0); }
}