/* ==========================================================================
   Modern HTML Login Template - Stylesheet
   ========================================================================== */

/* CSS Variables for design tokens */
:root {
    --font-primary: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Colors */
    --bg-main: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: rgba(99, 102, 241, 0.15);
    
    --input-bg: rgba(15, 23, 42, 0.6);
    --input-border: rgba(255, 255, 255, 0.12);
    --input-border-focus: #6366f1;
    
    --error: #ef4444;
    --error-bg: rgba(239, 68, 68, 0.1);
    --success: #22c55e;
    --success-bg: rgba(34, 197, 94, 0.1);
    
    --shadow-card: 0 25px 50px -12px rgba(0, 0, 0, 0.4), 0 0 30px rgba(99, 102, 241, 0.1);
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
    
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-main);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    overflow-x: hidden;
    position: relative;
}

/* Ambient Background Glow Shapes */
.background-decor {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
}

.circle {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.35;
}

.circle-1 {
    top: -10%;
    left: -10%;
    width: 450px;
    height: 450px;
    background: #6366f1;
}

.circle-2 {
    bottom: -10%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: #a855f7;
}

/* Main Container & Card */
.login-container {
    width: 100%;
    max-width: 440px;
    z-index: 1;
    perspective: 1000px;
}

.login-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 2.5rem 2rem;
    width: 100%;
    transition: var(--transition);
}

/* Card Header */
.card-header {
    text-align: center;
    margin-bottom: 2rem;
}

.brand-logo {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, var(--primary), #a855f7);
    border-radius: var(--radius-md);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    margin-bottom: 1.25rem;
    box-shadow: 0 8px 16px rgba(99, 102, 241, 0.3);
}

.card-header h2 {
    font-size: 1.65rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.card-header p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* Form Layout */
.login-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* Input Fields */
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 0.9rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    pointer-events: none;
    transition: var(--transition);
}

.input-wrapper input {
    width: 100%;
    padding: 0.75rem 2.6rem 0.75rem 2.6rem;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.92rem;
    outline: none;
    transition: var(--transition);
}

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

.input-wrapper input:focus {
    border-color: var(--input-border-focus);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.input-wrapper input:focus + .input-icon,
.input-wrapper:focus-within .input-icon {
    color: var(--primary);
}

/* Password Toggle Button */
.toggle-password {
    position: absolute;
    right: 0.75rem;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.toggle-password:hover {
    color: var(--text-primary);
    background-color: rgba(255, 255, 255, 0.05);
}

/* Error Text & States */
.error-text {
    font-size: 0.78rem;
    color: var(--error);
    min-height: 1rem;
    display: block;
}

.form-group.has-error input {
    border-color: var(--error);
}

.form-group.has-error input:focus {
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

/* Alert Notification Banner */
.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    line-height: 1.4;
    text-align: center;
    animation: fadeIn 0.3s ease-out;
}

.alert.error {
    background-color: var(--error-bg);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--error);
}

.alert.success {
    background-color: var(--success-bg);
    border: 1px solid rgba(34, 197, 94, 0.3);
    color: var(--success);
}

/* Checkbox & Options */
.form-options {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.85rem;
    margin-top: -0.25rem;
}

.checkbox-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    user-select: none;
    color: var(--text-secondary);
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    height: 18px;
    width: 18px;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: 4px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.checkbox-container:hover input ~ .checkmark {
    border-color: var(--primary);
}

.checkbox-container input:checked ~ .checkmark {
    background-color: var(--primary);
    border-color: var(--primary);
}

.checkmark::after {
    content: "";
    width: 5px;
    height: 9px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
    display: none;
    margin-bottom: 2px;
}

.checkbox-container input:checked ~ .checkmark::after {
    display: block;
}

.forgot-password-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.forgot-password-link:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Submit Button */
.submit-btn {
    width: 100%;
    padding: 0.85rem;
    background: linear-gradient(135deg, var(--primary), var(--primary-hover));
    color: #ffffff;
    border: none;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.35);
    transition: var(--transition);
    margin-top: 0.5rem;
}

.submit-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(99, 102, 241, 0.45);
}

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

.btn-spinner {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #ffffff;
    animation: spin 0.8s linear infinite;
}

/* Divider */
.divider {
    display: flex;
    align-items: center;
    text-align: center;
    margin: 1.75rem 0 1.25rem;
}

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

.divider span {
    padding: 0 0.75rem;
    color: var(--text-muted);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Social Buttons */
.social-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    padding: 0.65rem 1rem;
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.social-btn:hover {
    background-color: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.2);
}

/* Footer Link */
.card-footer {
    text-align: center;
    margin-top: 1.75rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.signup-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    margin-left: 0.25rem;
    transition: var(--transition);
}

.signup-link:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Utilities */
.hidden {
    display: none !important;
}

/* Animations */
@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive adjustments */
@media (max-width: 480px) {
    body {
        padding: 1rem;
    }
    
    .login-card {
        padding: 2rem 1.25rem;
    }

    .social-buttons {
        grid-template-columns: 1fr;
    }
}