/* ============================================
   K36 - Login Page Styles (WeChat-Inspired)
   ============================================ */

.login-container {
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(circle at 18% 20%, rgba(124,140,255,0.28), transparent 28%),
                radial-gradient(circle at 82% 72%, rgba(89,103,242,0.18), transparent 30%),
                linear-gradient(160deg, #F8FAFF 0%, #F1F4FF 48%, #EEF1FF 100%);
    position: relative;
    overflow: hidden;
    padding: 1rem;
}

/* 背景装饰 */
.login-bg-shapes {
    position: absolute;
    inset: 0;
    pointer-events: none;
    overflow: hidden;
}

.shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.12;
}

.shape-1 {
    width: clamp(200px, 40vw, 400px);
    height: clamp(200px, 40vw, 400px);
    background: var(--primary);
    top: -10%;
    right: -5%;
    animation: float 8s ease-in-out infinite;
}

.shape-2 {
    width: clamp(150px, 25vw, 250px);
    height: clamp(150px, 25vw, 250px);
    background: #7B94FF;
    bottom: 10%;
    left: -5%;
    animation: float 6s ease-in-out infinite reverse;
}

.shape-3 {
    width: clamp(100px, 15vw, 180px);
    height: clamp(100px, 15vw, 180px);
    background: var(--primary-light);
    top: 40%;
    left: 45%;
    animation: float 7s ease-in-out 1s infinite;
}

/* 登录卡片 */
.login-card {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255, 255, 255, 0.78);
    border-radius: var(--radius-xl);
    padding: clamp(1.5rem, 4vw, 2.2rem) clamp(1.5rem, 4vw, 2rem);
    width: min(92vw, 380px);
    box-shadow: 0 24px 70px rgba(38, 48, 100, 0.14), 0 2px 10px rgba(89,103,242,0.08);
    animation: fadeInUp 0.5s ease;
}

/* Logo 区域 */
.login-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.logo-icon {
    width: clamp(48px, 10vw, 60px);
    height: clamp(48px, 10vw, 60px);
    margin: 0 auto 0.8rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 16px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.logo-icon img {
    width: 60%;
    height: 60%;
    object-fit: contain;
}

.login-header h1 {
    font-size: clamp(1.5rem, 4vw, 1.8rem);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.05em;
    margin-bottom: 0.2rem;
}

.subtitle {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Tab 切换 */
.tab-switch {
    display: flex;
    position: relative;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    padding: 3px;
    margin-bottom: 1.5rem;
}

.tab-btn {
    flex: 1;
    padding: 0.45rem;
    border-radius: var(--radius-xs);
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-muted);
    transition: all var(--transition-normal);
    position: relative;
    z-index: 1;
}

.tab-btn.active {
    color: var(--primary);
}

.tab-slider {
    position: absolute;
    top: 3px;
    left: 3px;
    width: calc(50% - 3px);
    height: calc(100% - 6px);
    background: #fff;
    border-radius: var(--radius-xs);
    box-shadow: 0 8px 18px rgba(30,42,90,0.08);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 0;
}

/* 表单 */
.auth-form {
    display: none;
    animation: fadeIn 0.3s ease;
}

.auth-form.active {
    display: block;
}

.form-error {
    color: #F43530;
    font-size: 0.82rem;
    margin-bottom: 0.8rem;
    text-align: center;
    min-height: 1.2em;
}

/* 登录按钮 */
.auth-form .btn-primary {
    width: 100%;
    margin-top: 0.5rem;
    padding: 0.7rem;
    font-size: 0.95rem;
    letter-spacing: 0.08em;
}

/* 底部版权 */
.login-footer {
    position: absolute;
    bottom: clamp(0.5rem, 2vw, 1rem);
    text-align: center;
    width: 100%;
    color: var(--text-muted);
    font-size: 0.75rem;
    pointer-events: none;
}