:root { 
    --primary: #007AFF;
    --primary-dark: #0056CC;
    --primary-light: #4DA3FF;
    --secondary: #5856D6;
    --accent: #00C7BE;
    --gradient-primary: linear-gradient(135deg, #007AFF 0%, #5856D6 100%);
    --gradient-secondary: linear-gradient(135deg, #00C7BE 0%, #007AFF 100%);

    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-tertiary: #E8E8ED;
    --text-primary: #1D1D1F;
    --text-secondary: #6E6E73;
    --text-tertiary: #86868B;

    --glass-bg: rgba(255, 255, 255, 0.75);
    --glass-bg-strong: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.6);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    --glass-shadow-hover: 0 16px 48px rgba(0, 0, 0, 0.15);

    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 28px;
    --radius-xl: 32px;

    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    --transition-bounce: 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

.auth-background {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
    animation: floatOrb 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    top: -15%;
    right: -10%;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    bottom: 10%;
    left: -10%;
    animation-delay: -7s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    bottom: -5%;
    right: 20%;
    animation-delay: -14s;
}

@keyframes floatOrb {
    0%, 100% { 
        transform: translate(0, 0) scale(1); 
    }
    25% { 
        transform: translate(30px, -30px) scale(1.05); 
    }
    50% { 
        transform: translate(-20px, 20px) scale(0.95); 
    }
    75% { 
        transform: translate(15px, -15px) scale(1.02); 
    }
}

.auth-container {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 24px;
    position: relative;
    z-index: 1;
}

.glass-card {
    background: var(--glass-bg-strong);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--glass-shadow);
    transition: all var(--transition-normal);
}

.signup-card {
    width: 100%;
    max-width: 440px;
    padding: 48px 40px;
    animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    opacity: 0;
    transform: translateY(30px);
}

@keyframes slideUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.signup-card:hover {
    box-shadow: var(--glass-shadow-hover);
}

.card-header {
    text-align: center;
    margin-bottom: 36px;
}

.logo-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-primary);
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: white;
    box-shadow: 0 8px 24px rgba(0, 122, 255, 0.3);
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.1s;
    opacity: 0;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card-title {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    margin-bottom: 8px;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.15s;
    opacity: 0;
}

.card-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 400;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.2s;
    opacity: 0;
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.input-group {
    position: relative;
    animation: fadeInUp 0.5s ease forwards;
    opacity: 0;
}

.input-group:nth-child(2) {
    animation-delay: 0.25s;
}

.input-group:nth-child(3) {
    animation-delay: 0.3s;
}

.input-group:nth-child(4) {
    animation-delay: 0.35s;
}

.input-group input {
    width: 100%;
    padding: 18px 20px;
    font-size: 1rem;
    font-family: inherit;
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.6);
    border: 2px solid rgba(0, 0, 0, 0.06);
    border-radius: var(--radius-md);
    outline: none;
    transition: all var(--transition-normal);
}

.input-group input:focus {
    background: rgba(255, 255, 255, 0.9);
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.input-group input:focus + label,
.input-group input:not(:placeholder-shown) + label {
    transform: translateY(-28px) scale(0.85);
    color: var(--primary);
    font-weight: 500;
}

.input-group label {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1rem;
    color: var(--text-tertiary);
    pointer-events: none;
    transition: all var(--transition-normal);
    transform-origin: left center;
    background: transparent;
    padding: 0 4px;
}

.input-group input::placeholder {
    color: transparent;
}

.input-highlight {
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: all var(--transition-normal);
    transform: translateX(-50%);
    border-radius: 2px;
}

.input-group input:focus ~ .input-highlight {
    width: calc(100% - 40px);
}

.password-group {
    position: relative;
}

.password-group input {
    padding-right: 56px;
}

.password-toggle {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-tertiary);
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    border-radius: 8px;
}

.password-toggle:hover {
    color: var(--primary);
    background: rgba(0, 122, 255, 0.1);
}

.password-toggle .eye-closed {
    display: none;
}

.password-toggle.active .eye-open {
    display: none;
}

.password-toggle.active .eye-closed {
    display: block;
}

.btn-submit {
    position: relative;
    width: 100%;
    padding: 18px 32px;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    color: white;
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 20px rgba(0, 122, 255, 0.35);
    animation: fadeInUp 0.5s ease forwards;
    animation-delay: 0.4s;
    opacity: 0;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 122, 255, 0.45);
}

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

.btn-submit:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.btn-submit .btn-text {
    transition: opacity var(--transition-fast);
}

.btn-submit .btn-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.btn-submit.loading .btn-text {
    opacity: 0;
}

.btn-submit.loading .btn-loader {
    opacity: 1;
}

.spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.error-message,
.success-message {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    display: none;
    animation: shakeIn 0.4s ease;
}

@keyframes shakeIn {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-8px); }
    40% { transform: translateX(8px); }
    60% { transform: translateX(-4px); }
    80% { transform: translateX(4px); }
}

.error-message {
    background: rgba(255, 59, 48, 0.1);
    color: #FF3B30;
    border: 1px solid rgba(255, 59, 48, 0.2);
}

.error-message.show {
    display: block;
}

.success-message {
    background: rgba(52, 199, 89, 0.1);
    color: #34C759;
    border: 1px solid rgba(52, 199, 89, 0.2);
}

.success-message.show {
    display: block;
}

.card-footer {
    text-align: center;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    animation: fadeInUp 0.5s ease forwards;
    animation-delay: 0.45s;
    opacity: 0;
}

.card-footer p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.auth-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-fast);
    position: relative;
}

.auth-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--transition-fast);
}

.auth-link:hover::after {
    width: 100%;
}

.minimal-footer {
    text-align: center;
    padding: 24px;
    position: relative;
    z-index: 1;
}

.minimal-footer p {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
}

@media (max-width: 480px) {
    .signup-card {
        padding: 36px 24px;
        border-radius: var(--radius-lg);
    }

    .card-title {
        font-size: 1.5rem;
    }

    .card-subtitle {
        font-size: 0.9rem;
    }

    .input-group input {
        padding: 16px 18px;
    }

    .btn-submit {
        padding: 16px 28px;
    }

    .logo-icon {
        width: 56px;
        height: 56px;
    }

    .gradient-orb {
        filter: blur(60px);
        opacity: 0.4;
    }

    .orb-1 {
        width: 300px;
        height: 300px;
    }

    .orb-2 {
        width: 250px;
        height: 250px;
    }

    .orb-3 {
        width: 200px;
        height: 200px;
    }
}

@media (min-width: 481px) and (max-width: 768px) {
    .signup-card {
        max-width: 400px;
        padding: 40px 32px;
    }
}

@media (min-width: 769px) {
    .signup-card {
        max-width: 440px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}