:root {
    --bg: #f6f3ee;
    --surface: #ffffff;
    --input-bg: #ffffff;
    --primary: #c0a687;
    --primary-glow: rgba(192, 166, 135, 0.4);
    --text-main: #3f312b;
    --text-muted: #8a766c;
    --border: rgba(63, 49, 43, 0.15);
    --error: #f85149;
    --line-green: #06c755;
    --google-red: #ea4335;
}

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    overflow-x: hidden;
    box-sizing: border-box;
    padding: 2rem 0;
    background-image: 
        radial-gradient(circle at 20% 20%, rgba(59, 130, 246, 0.05) 0%, transparent 40%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.05) 0%, transparent 40%);
}

.auth-container {
    width: 100%;
    max-width: 420px;
    padding: 1rem;
    animation: fadeIn 0.8s ease-out;
}

.auth-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1.75rem;
    padding: 2rem 1.9rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
    position: relative;
    overflow: hidden;
}

.auth-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 4px;
    background: linear-gradient(90deg, var(--primary), #8b5cf6);
}

.logo-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 1.25rem;
    text-align: center;
}

.logo-box {
    width: 44px;
    height: 44px;
    background: var(--primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 0.6rem;
    box-shadow: 0 0 20px var(--primary-glow);
}

.brand-name {
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin: 0;
}

.brand-subtitle {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.35rem;
}

/* Forms */
.form-group {
    margin-bottom: 0.85rem;
}

label {
    display: block;
    font-size: 0.78rem;
    font-weight: 600;
    margin-bottom: 0.4rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

input {
    width: 100%;
    box-sizing: border-box;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: 9px;
    padding: 0.7rem 0.95rem;
    color: var(--text-main);
    font-family: inherit;
    font-size: 0.92rem;
    transition: 0.3s;
}

input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--primary-glow);
}

/* Password 顯示/隱藏切換 */
.pw-field {
    position: relative;
}

.pw-field input {
    padding-right: 44px;
}

.pw-toggle {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    color: var(--text-muted);
    transition: color 0.2s;
}

.pw-toggle:hover {
    color: var(--primary);
}

.pw-toggle svg {
    width: 20px;
    height: 20px;
    display: block;
}

.pw-field .icon-eye-off {
    display: none;
}

.pw-field.show .icon-eye {
    display: none;
}

.pw-field.show .icon-eye-off {
    display: block;
}

.btn {
    width: 100%;
    box-sizing: border-box;
    padding: 0.7rem;
    border-radius: 9px;
    font-weight: 700;
    font-size: 0.92rem;
    cursor: pointer;
    border: none;
    transition: 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    margin-top: 0.5rem;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 8px 16px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 24px var(--primary-glow);
}

.divider {
    display: flex;
    align-items: center;
    margin: 1rem 0;
    color: var(--text-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.divider::before, .divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.divider span { padding: 0 0.75rem; }

.btn-social {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
    font-size: 0.85rem;
}

.btn-social:hover {
    background: rgba(63, 49, 43, 0.04);
    border-color: var(--text-muted);
}

.btn-line { color: var(--line-green); border-color: rgba(6, 199, 85, 0.2); }
.btn-line:hover { background: rgba(6, 199, 85, 0.05); }

.error-message {
    color: var(--error);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    display: block;
}

.footer-links {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.footer-links a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}