/* ============================================================
   数道 · 万象 — 登录 / 注册 弹层
   黑金国风风格，复用全局设计变量（style.css 中的 :root）
   （独立文件，不改原有 app.js / style.css / teaching*）
   ============================================================ */

/* ---- 导航栏登录按钮 ---- */
.nav-auth-btn {
    font-family: var(--font-serif);
    font-size: 0.92rem;
    letter-spacing: 0.12em;
    color: var(--gold-bright);
    background: transparent;
    border: 1px solid rgba(212, 165, 116, 0.45);
    border-radius: 999px;
    padding: 7px 18px;
    margin-left: 14px;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
}

.nav-auth-btn:hover {
    background: rgba(212, 165, 116, 0.12);
    border-color: var(--gold-bright);
    box-shadow: 0 0 18px rgba(212, 165, 116, 0.25);
}

.nav-auth-btn.logged-in {
    color: var(--ink-black);
    background: linear-gradient(135deg, var(--gold), var(--gold-bright));
    border-color: var(--gold-bright);
    font-weight: 600;
}

.nav-auth-btn.logged-in:hover {
    box-shadow: 0 0 22px rgba(232, 196, 153, 0.5);
}

/* ---- 登录态下拉菜单 ---- */
.nav-auth-wrap {
    position: relative;
    display: inline-flex;
    align-items: center;
}

.nav-auth-menu {
    position: absolute;
    top: calc(100% + 12px);
    right: 0;
    min-width: 168px;
    background: rgba(13, 17, 23, 0.97);
    border: 1px solid rgba(212, 165, 116, 0.35);
    border-radius: var(--radius);
    padding: 8px;
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(8px);
    z-index: 1100;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-auth-menu.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.nav-auth-menu-name {
    font-family: var(--font-serif);
    color: var(--gold-bright);
    font-size: 0.95rem;
    padding: 8px 12px 10px;
    border-bottom: 1px solid rgba(212, 165, 116, 0.18);
    margin-bottom: 6px;
    letter-spacing: 0.06em;
}

.nav-auth-menu-item {
    display: block;
    width: 100%;
    text-align: left;
    background: transparent;
    border: none;
    color: var(--text-light);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    padding: 9px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.25s;
}

.nav-auth-menu-item:hover {
    background: rgba(212, 165, 116, 0.12);
    color: var(--gold-bright);
}

/* ============================================================
   弹层本体
   ============================================================ */
.auth-modal {
    position: fixed;
    inset: 0;
    z-index: 10003;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.4s ease, visibility 0.4s ease;
}

.auth-modal.open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.auth-backdrop {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 30%, rgba(20, 16, 10, 0.78), rgba(5, 5, 8, 0.92));
    backdrop-filter: blur(6px);
}

/* 国风暗纹背景 */
.auth-backdrop::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 18% 22%, rgba(212, 165, 116, 0.06) 0, transparent 38%),
        radial-gradient(circle at 82% 78%, rgba(192, 57, 43, 0.05) 0, transparent 40%);
    pointer-events: none;
}

.auth-card {
    position: relative;
    width: 420px;
    max-width: calc(100vw - 36px);
    background: linear-gradient(160deg, rgba(22, 27, 34, 0.98), rgba(13, 17, 23, 0.98));
    border: 1px solid rgba(212, 165, 116, 0.4);
    border-radius: 18px;
    padding: 38px 38px 32px;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.04);
    transform: translateY(24px) scale(0.96);
    opacity: 0;
    transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.45s ease;
}

.auth-modal.open .auth-card {
    transform: translateY(0) scale(1);
    opacity: 1;
}

/* 卡片顶部金线 */
.auth-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 28px;
    right: 28px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--gold), transparent);
}

.auth-close {
    position: absolute;
    top: 16px;
    right: 18px;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: transparent;
    border: 1px solid rgba(212, 165, 116, 0.25);
    color: var(--gold-dim);
    font-size: 1.2rem;
    line-height: 1;
    cursor: pointer;
    transition: all 0.3s;
}

.auth-close:hover {
    color: var(--gold-bright);
    border-color: var(--gold-bright);
    transform: rotate(90deg);
}

/* ---- 品牌 ---- */
.auth-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 22px;
}

.auth-logo {
    width: 38px;
    height: 38px;
    border-radius: 9px;
    background: linear-gradient(135deg, var(--gold), var(--gold-bright));
    color: var(--ink-black);
    font-family: var(--font-serif);
    font-weight: 900;
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 18px rgba(212, 165, 116, 0.3);
}

.auth-brand-name {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    letter-spacing: 0.18em;
    color: var(--gold-bright);
}

/* ---- Tabs ---- */
.auth-tabs {
    display: flex;
    gap: 8px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(212, 165, 116, 0.18);
    border-radius: 999px;
    padding: 4px;
    margin-bottom: 26px;
}

.auth-tab {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-dim);
    font-family: var(--font-serif);
    font-size: 1rem;
    letter-spacing: 0.2em;
    padding: 9px 0;
    border-radius: 999px;
    cursor: pointer;
    transition: all 0.3s;
}

.auth-tab.active {
    background: linear-gradient(135deg, var(--gold), var(--gold-bright));
    color: var(--ink-black);
    font-weight: 600;
    box-shadow: 0 4px 14px rgba(212, 165, 116, 0.3);
}

/* ---- 表单字段 ---- */
.auth-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.auth-field {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.auth-field label {
    font-family: var(--font-sans);
    font-size: 0.82rem;
    letter-spacing: 0.08em;
    color: var(--gold-dim);
}

.auth-field input {
    width: 100%;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(212, 165, 116, 0.22);
    border-radius: 10px;
    padding: 12px 14px;
    color: var(--text-light);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    transition: all 0.3s;
    outline: none;
}

.auth-field input::placeholder {
    color: var(--text-muted);
}

.auth-field input:focus {
    border-color: var(--gold-bright);
    background: rgba(212, 165, 116, 0.06);
    box-shadow: 0 0 0 3px rgba(212, 165, 116, 0.12);
}

/* 注册专属字段默认隐藏 */
.auth-field-extra {
    display: none;
}

.auth-modal.mode-register .auth-field-extra {
    display: flex;
    animation: auth-fade-in 0.4s ease;
}

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

/* 密码可见切换 */
.auth-pwd-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.auth-pwd-wrap input {
    padding-right: 44px;
}

.auth-pwd-toggle {
    position: absolute;
    right: 8px;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1.05rem;
    opacity: 0.7;
    transition: opacity 0.25s;
    padding: 4px;
}

.auth-pwd-toggle:hover {
    opacity: 1;
}

/* ---- 错误提示 ---- */
.auth-error {
    color: var(--vermilion-light);
    font-size: 0.83rem;
    letter-spacing: 0.03em;
    min-height: 1.1em;
    margin: -2px 0 2px;
    text-align: left;
}

/* ---- 提交按钮 ---- */
.auth-submit {
    margin-top: 6px;
    width: 100%;
    background: linear-gradient(135deg, var(--gold), var(--gold-bright));
    color: var(--ink-black);
    border: none;
    border-radius: 10px;
    padding: 13px 0;
    font-family: var(--font-serif);
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: 0.3em;
    cursor: pointer;
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 8px 24px rgba(212, 165, 116, 0.25);
}

.auth-submit:hover {
    box-shadow: 0 12px 32px rgba(232, 196, 153, 0.45);
    transform: translateY(-2px);
}

.auth-submit:active {
    transform: translateY(0);
}

/* ---- 切换提示 ---- */
.auth-switch {
    text-align: center;
    margin-top: 20px;
    font-size: 0.88rem;
    color: var(--text-dim);
    letter-spacing: 0.04em;
}

.auth-switch a {
    color: var(--gold-bright);
    text-decoration: none;
    margin-left: 4px;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s;
    cursor: pointer;
}

.auth-switch a:hover {
    border-color: var(--gold-bright);
}

/* ---- 登录态隐藏自定义光标（弹层内用系统光标）---- */
body.auth-open .cursor-dot,
body.auth-open .cursor-ring {
    opacity: 0 !important;
}

body.auth-open {
    overflow: hidden;
}

/* ---- 响应式 ---- */
@media (max-width: 520px) {
    .auth-card {
        padding: 30px 22px 26px;
    }
    .nav-auth-btn {
        padding: 6px 13px;
        font-size: 0.82rem;
        margin-left: 8px;
    }
}