/* === CSS Reset === */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* === Design Tokens === */
:root {
    --bg: #000000;
    --card-bg: rgba(28, 28, 30, 0.88);
    --card-border: rgba(255, 255, 255, 0.08);
    --input-bg: #1c1c1e;
    --input-border: rgba(255, 255, 255, 0.12);
    --input-focus: rgba(255, 255, 255, 0.25);
    --text-primary: #ffffff;
    --text-secondary: #999999;
    --text-muted: #666666;
    --btn-primary-bg: rgba(255, 255, 255, 0.92);
    --btn-primary-text: #000000;
    --btn-secondary-bg: rgba(255, 255, 255, 0.06);
    --btn-secondary-border: rgba(255, 255, 255, 0.15);
    --error: #ff453a;
    --tab-bg: rgba(255, 255, 255, 0.08);
    --tab-active: rgba(255, 255, 255, 0.18);
    --radius-card: 20px;
    --radius-input: 10px;
    --radius-btn: 10px;
}

/* === Base Styles === */
body {
    font-family: -apple-system, 'SF Pro Display', 'Segoe UI', system-ui, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg);
    color: var(--text-primary);
    padding: 2rem;
    overflow-x: hidden;
    overflow-y: auto;
    position: relative;
}

/* === Aurora Background Animation === */
.aurora-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.aurora-bg::before,
.aurora-bg::after {
    content: '';
    position: absolute;
    width: 150%;
    height: 60%;
    border-radius: 40%;
    filter: blur(80px);
    opacity: 0.55;
}

.aurora-bg::before {
    background: linear-gradient(
        120deg,
        #ff0040 0%,
        #ff6a00 15%,
        #ffdd00 28%,
        #00ff6a 42%,
        #00d4ff 58%,
        #4400ff 72%,
        #aa00ff 85%,
        #ff0040 100%
    );
    top: 40%;
    left: -30%;
    animation: auroraFlow1 12s ease-in-out infinite alternate;
}

.aurora-bg::after {
    background: linear-gradient(
        300deg,
        #ff006620 0%,
        #ff440030 20%,
        #00ffaa25 40%,
        #0066ff30 60%,
        #aa00ff20 80%,
        #ff006620 100%
    );
    bottom: 20%;
    right: -30%;
    animation: auroraFlow2 15s ease-in-out infinite alternate;
}

/* Third aurora layer using a child div */
.aurora-glow {
    position: absolute;
    width: 120%;
    height: 40%;
    top: 30%;
    left: -10%;
    background: linear-gradient(
        90deg,
        transparent 0%,
        #ff004020 10%,
        #ff880030 20%,
        #44ff0025 35%,
        #00aaff35 50%,
        #6600ff30 65%,
        #ff00aa25 80%,
        transparent 100%
    );
    filter: blur(60px);
    border-radius: 50%;
    animation: auroraFlow3 10s ease-in-out infinite alternate;
    pointer-events: none;
}

@keyframes auroraFlow1 {
    0% {
        transform: translateX(-15%) translateY(5%) rotate(-5deg) scale(1);
    }
    50% {
        transform: translateX(10%) translateY(-10%) rotate(3deg) scale(1.1);
    }
    100% {
        transform: translateX(20%) translateY(8%) rotate(-3deg) scale(0.95);
    }
}

@keyframes auroraFlow2 {
    0% {
        transform: translateX(10%) translateY(0%) rotate(5deg) scale(1.05);
    }
    50% {
        transform: translateX(-15%) translateY(10%) rotate(-4deg) scale(0.9);
    }
    100% {
        transform: translateX(-5%) translateY(-8%) rotate(2deg) scale(1.1);
    }
}

@keyframes auroraFlow3 {
    0% {
        transform: translateX(-5%) scaleX(1) scaleY(0.8);
        opacity: 0.4;
    }
    50% {
        transform: translateX(8%) scaleX(1.15) scaleY(1.1);
        opacity: 0.6;
    }
    100% {
        transform: translateX(-8%) scaleX(0.9) scaleY(0.9);
        opacity: 0.35;
    }
}

/* === Centered Container === */
.container {
    text-align: center;
    position: relative;
    z-index: 1;
}

.container h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin-bottom: 0.5rem;
}

.container p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* === Buttons === */
.btn-group {
    margin-top: 1.5rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.6rem;
    border-radius: var(--radius-btn);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.25s ease;
    cursor: pointer;
    border: none;
    font-family: inherit;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
}

.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
}

.btn-primary:hover {
    background: rgba(255, 255, 255, 1);
    box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
}

.btn-secondary {
    background: var(--btn-secondary-bg);
    color: var(--text-primary);
    border: 1px solid var(--btn-secondary-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.25);
}

/* === Tab Toggle (Sign up / Sign in) === */
.tab-toggle {
    display: flex;
    background: var(--tab-bg);
    border-radius: 50px;
    padding: 4px;
    margin-bottom: 1.75rem;
    width: fit-content;
}

.tab-toggle a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    transition: all 0.25s ease;
}

.tab-toggle a.active {
    background: var(--tab-active);
    color: var(--text-primary);
    font-weight: 600;
}

.tab-toggle a:hover:not(.active) {
    color: var(--text-primary);
}

/* === Close Button === */
.close-btn {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--text-secondary);
    cursor: pointer;
    text-decoration: none;
    font-size: 1.1rem;
    transition: all 0.2s ease;
    line-height: 1;
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
}

/* === Back Link (now hidden, replaced by close btn) === */
.back-link {
    display: none;
}

/* === Form Styles === */
.form-container {
    background: var(--card-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    padding: 2.5rem;
    border-radius: var(--radius-card);
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.4);
    width: 100%;
    max-width: 420px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.form-step {
    display: none;
}

.form-step.active {
    display: block;
    animation: fadeIn 0.35s ease-out;
}

.hidden {
    display: none !important;
}

.form-step h2 {
    margin-bottom: 0.4rem;
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

.highlight-email {
    font-weight: 600;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 1.2rem;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 0.4rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid var(--input-border);
    border-radius: var(--radius-input);
    font-family: inherit;
    font-size: 0.95rem;
    transition: border-color 0.25s, box-shadow 0.25s;
    background: var(--input-bg);
    color: var(--text-primary);
}

.form-group input::placeholder {
    color: var(--text-muted);
}

.form-group input:focus {
    outline: none;
    border-color: var(--input-focus);
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.05);
}

.btn-block {
    width: 100%;
    display: block;
    padding: 0.85rem;
}

.mt-1 {
    margin-top: 0.75rem;
}

.error-msg {
    color: var(--error);
    font-size: 0.85rem;
    margin-bottom: 1rem;
    min-height: 1.2em;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* === Responsive === */
@media (max-width: 480px) {
    body {
        padding: 1rem;
    }

    .form-container {
        padding: 2rem 1.5rem;
        border-radius: 16px;
    }
}

/* === Or Divider === */
.divider {
    display: flex;
    align-items: center;
    margin: 1.25rem 0;
    gap: 1rem;
}

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

.divider span {
    font-size: 0.82rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: lowercase;
}

/* === Google Sign-In Button Container === */
.g_id_signin {
    display: flex;
    justify-content: center;
}

/* === Signup OTP Verification Cards === */
.otp-verify-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 14px;
    padding: 1.25rem;
    margin-bottom: 1rem;
    transition: border-color 0.4s ease, background 0.4s ease, box-shadow 0.4s ease;
}

.otp-verify-card:hover:not(.verified) {
    border-color: rgba(255, 255, 255, 0.18);
    background: rgba(255, 255, 255, 0.06);
}

.otp-verify-card.verified {
    border-color: rgba(52, 199, 89, 0.5);
    background: rgba(52, 199, 89, 0.06);
    box-shadow: 0 0 20px rgba(52, 199, 89, 0.08);
}

.otp-verify-card-header {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    margin-bottom: 1rem;
}

.otp-verify-card-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-primary);
    flex-shrink: 0;
    transition: background 0.3s ease;
}

.otp-verify-card.verified .otp-verify-card-icon {
    background: rgba(52, 199, 89, 0.15);
    color: #34c759;
}

.otp-verify-card-info {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
    flex: 1;
    min-width: 0;
}

.otp-verify-card-title {
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--text-primary);
}

.otp-verify-card-dest {
    font-size: 0.8rem;
    color: var(--text-muted);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* === OTP Digit Inputs (shared across signin + signup) === */
.otp-input-group {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    margin-bottom: 1.2rem;
}

.otp-digit {
    width: 46px;
    height: 54px;
    text-align: center;
    font-size: 1.4rem;
    font-weight: 700;
    font-family: inherit;
    border: 1px solid var(--input-border);
    border-radius: 10px;
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
    background: var(--input-bg);
    color: var(--text-primary);
}

.otp-digit:focus {
    border-color: var(--input-focus);
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.05);
}

.otp-digit.filled {
    border-color: rgba(255, 255, 255, 0.3);
}

.otp-digit:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.verified-badge {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    margin-left: auto;
    font-size: 0.78rem;
    font-weight: 600;
    color: #34c759;
    background: rgba(52, 199, 89, 0.12);
    border: 1px solid rgba(52, 199, 89, 0.3);
    border-radius: 50px;
    padding: 0.25rem 0.6rem;
    white-space: nowrap;
    flex-shrink: 0;
    animation: badgePop 0.3s ease-out;
}

@keyframes badgePop {
    0% { transform: scale(0.6); opacity: 0; }
    60% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

/* Verify OTP button inside cards */
.btn-verify-otp {
    margin-top: 0.25rem;
    font-size: 0.88rem;
    padding: 0.7rem 1.2rem;
}

.btn-verify-otp.btn-verified {
    background: rgba(52, 199, 89, 0.15) !important;
    color: #34c759 !important;
    border: 1px solid rgba(52, 199, 89, 0.3);
}

.btn-primary.ready {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
}

/* Responsive tweaks for OTP digits */
@media (max-width: 440px) {
    .otp-digit {
        width: 38px;
        height: 46px;
        font-size: 1.1rem;
    }

    .otp-input-group {
        gap: 0.3rem;
    }
}