/* ============================================================================
   RESET & BASE STYLES
   ============================================================================ */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    color: #1a1a1a;
    background: #ffffff;
    line-height: 1.6;
}

/* ============================================================================
   COLOR PALETTE & TOKENS
   ============================================================================ */

:root {
    /* Primary Colors */
    --color-primary: #0066ff;
    --color-primary-light: #e6f0ff;
    --color-primary-dark: #0052cc;
    
    /* Neutral Colors */
    --color-text-primary: #1a1a1a;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8f9fa;
    --color-bg-tertiary: #f0f2f5;
    --color-border: #e0e0e0;
    --color-border-light: #f0f0f0;
    
    /* Status Colors */
    --color-success: #10b981;
    --color-danger: #ef4444;
    --color-warning: #f59e0b;
    --color-info: #3b82f6;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px 0 rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px 0 rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 20px 40px 0 rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================================================
   LOGIN PAGE LAYOUT
   ============================================================================ */

.login-page {
    display: flex;
    min-height: 100vh;
    background: linear-gradient(135deg, #fafbfc 0%, #f5f7fa 100%);
    align-items: center;
    justify-content: center;
}

.login-shell {
    display: flex;
    width: 100%;
    height: 100vh;
    gap: 0;
}

/* ============================================================================
   LOGIN VISUAL SECTION (LEFT SIDE)
   ============================================================================ */

.login-visual {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: var(--spacing-2xl);
    background: linear-gradient(135deg, #0066ff 0%, #0052cc 100%);
    color: #ffffff;
    position: relative;
    overflow: hidden;
}

.login-visual::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.04) 0%, transparent 50%);
    pointer-events: none;
}

.login-visual > * {
    position: relative;
    z-index: 1;
}

/* Brand Section */

.login-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.brand-mark {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.12);
    border: 1.5px solid rgba(255, 255, 255, 0.25);
    border-radius: var(--radius-lg);
    font-size: 24px;
    font-weight: 700;
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
}

.login-brand:hover .brand-mark {
    background: rgba(255, 255, 255, 0.18);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-2px);
}

.login-brand strong {
    display: block;
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.login-brand small {
    display: block;
    font-size: 13px;
    font-weight: 400;
    opacity: 0.8;
    margin-top: 4px;
}

/* Copy Section */

.login-copy {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.login-kicker {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    opacity: 0.75;
    margin-bottom: var(--spacing-lg);
}

.login-copy h1 {
    font-size: 36px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.5px;
}

.login-copy p {
    font-size: 16px;
    line-height: 1.6;
    opacity: 0.92;
    max-width: 500px;
}

/* Signal Grid (Decorative) */

.login-signal-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--spacing-md);
    margin-top: auto;
    opacity: 0.12;
}

.login-signal-grid span {
    aspect-ratio: 1;
    background: rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
    animation: pulse-grid 3s ease-in-out infinite;
}

.login-signal-grid span:nth-child(1) { animation-delay: 0s; }
.login-signal-grid span:nth-child(2) { animation-delay: 0.2s; }
.login-signal-grid span:nth-child(3) { animation-delay: 0.4s; }
.login-signal-grid span:nth-child(4) { animation-delay: 0.6s; }
.login-signal-grid span:nth-child(5) { animation-delay: 0.8s; }
.login-signal-grid span:nth-child(6) { animation-delay: 1s; }

@keyframes pulse-grid {
    0%, 100% { opacity: 0.12; transform: scale(1); }
    50% { opacity: 0.25; transform: scale(1.05); }
}

/* ============================================================================
   LOGIN PANEL SECTION (RIGHT SIDE - CENTERED)
   ============================================================================ */

.login-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-2xl);
    background: #ffffff;
    overflow-y: auto;
}

.login-container {
    width: 100%;
    max-width: 420px;
}

.login-card {
    background: #ffffff;
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    animation: fadeIn var(--transition-base) ease-out;
}

.login-card:hover {
    border-color: var(--color-border);
    box-shadow: var(--shadow-md);
}

.login-card-head {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.login-card-head h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.3px;
}

.login-card-head .muted {
    font-size: 14px;
    color: var(--color-text-muted);
    font-weight: 400;
}

/* ============================================================================
   FORM STYLES
   ============================================================================ */

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 14px;
    font-size: 14px;
    font-family: inherit;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: #ffffff;
    color: var(--color-text-primary);
    transition: all var(--transition-base);
    outline: none;
}

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

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
    background: #ffffff;
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
    font-family: inherit;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

/* ============================================================================
   BUTTON STYLES
   ============================================================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.3px;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    outline: none;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #ffffff;
    width: 100%;
    box-shadow: 0 2px 8px rgba(0, 102, 255, 0.2);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 102, 255, 0.3);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(0, 102, 255, 0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
    width: 100%;
}

.btn-secondary:hover:not(:disabled) {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
}

.btn-secondary:active:not(:disabled) {
    background: #cce0ff;
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    width: auto;
    padding: 10px 20px;
    font-size: 13px;
}

.btn-ghost:hover:not(:disabled) {
    background: var(--color-bg-secondary);
    border-color: var(--color-border);
}

/* ============================================================================
   SIGNUP LINK
   ============================================================================ */

.signup-link-container {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border-light);
    text-align: center;
}

.signup-link-text {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.signup-link-text strong {
    font-weight: 600;
}

.btn-signup {
    display: inline-block;
    margin-top: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #ffffff;
    padding: 12px 32px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: 0 2px 8px rgba(0, 102, 255, 0.2);
}

.btn-signup:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 102, 255, 0.3);
}

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

/* ============================================================================
   MODAL STYLES
   ============================================================================ */

.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: fadeInOverlay var(--transition-base) ease-out;
}

.modal-overlay.active {
    display: flex;
}

@keyframes fadeInOverlay {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal {
    background: #ffffff;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp var(--transition-base) ease-out;
    position: relative;
}

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

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border-light);
    position: sticky;
    top: 0;
    background: #ffffff;
    z-index: 10;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    color: var(--color-text-muted);
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.modal-close:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
}

.modal-body {
    padding: var(--spacing-xl);
}

.modal-footer {
    padding: var(--spacing-xl);
    border-top: 1px solid var(--color-border-light);
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    background: var(--color-bg-secondary);
}

.modal-footer .btn {
    width: auto;
}

/* ============================================================================
   ALERT STYLES
   ============================================================================ */

.alert {
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: 14px;
    margin-bottom: var(--spacing-lg);
    border-left: 4px solid;
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    animation: slideDown var(--transition-base) ease-out;
}

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

.alert-danger {
    background: #fef2f2;
    border-color: var(--color-danger);
    color: #7f1d1d;
}

.alert-success {
    background: #f0fdf4;
    border-color: var(--color-success);
    color: #15803d;
}

.alert-warning {
    background: #fffbeb;
    border-color: var(--color-warning);
    color: #92400e;
}

.alert-info {
    background: #eff6ff;
    border-color: var(--color-info);
    color: #1e40af;
}

/* ============================================================================
   RESPONSIVE DESIGN
   ============================================================================ */

@media (max-width: 1024px) {
    .login-shell {
        flex-direction: column;
        height: auto;
    }

    .login-visual {
        min-height: 50vh;
        padding: var(--spacing-xl);
    }

    .login-panel {
        min-height: 50vh;
        padding: var(--spacing-xl);
    }

    .login-copy h1 {
        font-size: 28px;
    }
}

@media (max-width: 768px) {
    .login-visual {
        padding: var(--spacing-lg);
        min-height: 40vh;
    }

    .login-panel {
        padding: var(--spacing-lg);
        min-height: auto;
    }

    .login-container {
        max-width: 100%;
    }

    .login-copy h1 {
        font-size: 24px;
    }

    .login-copy p {
        font-size: 14px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .login-signal-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .modal {
        width: 95%;
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 14px;
    }

    .login-shell {
        height: auto;
    }

    .login-visual {
        padding: var(--spacing-md);
        min-height: 35vh;
    }

    .login-panel {
        padding: var(--spacing-md);
    }

    .login-container {
        max-width: 100%;
    }

    .login-card {
        padding: var(--spacing-lg);
    }

    .login-copy h1 {
        font-size: 20px;
    }

    .login-copy p {
        font-size: 13px;
    }

    .login-brand {
        margin-bottom: var(--spacing-lg);
    }

    .brand-mark {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    .login-brand strong {
        font-size: 16px;
    }

    .login-card-head h2 {
        font-size: 20px;
    }

    .modal-header {
        padding: var(--spacing-lg);
    }

    .modal-body {
        padding: var(--spacing-lg);
    }

    .modal-footer {
        padding: var(--spacing-lg);
        flex-direction: column;
    }

    .modal-footer .btn {
        width: 100%;
    }
}

/* ============================================================================
   UTILITY CLASSES
   ============================================================================ */

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

/* ============================================================================
   ANIMATIONS
   ============================================================================ */

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

/* ============================================================================
   DARK MODE SUPPORT
   ============================================================================ */

@media (prefers-color-scheme: dark) {
    :root {
        --color-text-primary: #f5f5f5;
        --color-text-secondary: #b0b0b0;
        --color-text-muted: #808080;
        --color-bg-primary: #1a1a1a;
        --color-bg-secondary: #242424;
        --color-bg-tertiary: #2d2d2d;
        --color-border: #3a3a3a;
        --color-border-light: #2d2d2d;
    }

    body {
        background: #1a1a1a;
        color: var(--color-text-primary);
    }

    .login-page {
        background: linear-gradient(135deg, #1a1a1a 0%, #242424 100%);
    }

    .login-panel {
        background: #1a1a1a;
    }

    .login-card {
        background: #242424;
        border-color: var(--color-border);
    }

    .form-group input,
    .form-group textarea {
        background: #2d2d2d;
        color: var(--color-text-primary);
        border-color: var(--color-border);
    }

    .form-group input:focus,
    .form-group textarea:focus {
        background: #333333;
        border-color: var(--color-primary);
    }

    .modal {
        background: #242424;
    }

    .modal-header {
        background: #242424;
        border-color: var(--color-border);
    }

    .modal-footer {
        background: #1a1a1a;
        border-color: var(--color-border);
    }

    .alert-danger {
        background: #3a1f1f;
        color: #fca5a5;
    }

    .alert-success {
        background: #1f3a2f;
        color: #86efac;
    }

    .btn-ghost {
        border-color: var(--color-border);
        color: var(--color-text-secondary);
    }

    .btn-ghost:hover:not(:disabled) {
        background: var(--color-bg-secondary);
    }

    .signup-link-container {
        border-color: var(--color-border-light);
    }
}