/* ===========================
   CSS Reset & Base Styles
   =========================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --primary: #667eea;
    --primary-dark: #5568d3;
    --primary-light: #7c94f5;
    --secondary: #764ba2;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    
    /* Neutrals */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --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-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: var(--spacing-lg);
    color: var(--gray-900);
    line-height: 1.6;
}

/* ===========================
   Container
   =========================== */
.container {
    max-width: 800px;
    margin: 0 auto;
    animation: fadeIn 0.6s ease;
}

/* ===========================
   Header
   =========================== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.view-submissions-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--gray-100);
    color: var(--gray-700);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.view-submissions-btn:hover {
    background: var(--gray-200);
    transform: translateY(-2px);
}

/* ===========================
   Cards
   =========================== */
.card {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    animation: slideUp 0.4s ease;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xl);
}

.card-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--spacing-xs);
}

.card-header p {
    color: var(--gray-500);
    font-size: 0.95rem;
}

.back-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: white;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    color: var(--gray-700);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.back-btn:hover {
    background: var(--gray-50);
    border-color: var(--gray-400);
}

/* ===========================
   Form Styles
   =========================== */
.form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-label {
    font-weight: 600;
    color: var(--gray-700);
    font-size: 0.95rem;
}

.required {
    color: var(--error);
    margin-left: 2px;
}

.form-input {
    padding: var(--spacing-md);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

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

.error-message {
    color: var(--error);
    font-size: 0.875rem;
    display: none;
}

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

/* ===========================
   Buttons
   =========================== */
.submit-btn {
    padding: var(--spacing-md) var(--spacing-xl);
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-height: 48px;
}

.submit-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* ===========================
   Messages
   =========================== */
.message {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-lg);
    animation: slideDown 0.3s ease;
}

.success-message {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.error-message-box {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.message svg {
    flex-shrink: 0;
    margin-top: 2px;
}

.message strong {
    display: block;
    margin-bottom: 4px;
}

.message p {
    margin: 0;
    font-size: 0.95rem;
}

/* ===========================
   Submissions List
   =========================== */
.submissions-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.stat-card {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

.submissions-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.submission-item {
    padding: var(--spacing-lg);
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.submission-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

.submission-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.submission-id {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary);
    background: var(--gray-100);
    padding: 4px 8px;
    border-radius: 4px;
}

.submission-timestamp {
    font-size: 0.85rem;
    color: var(--gray-500);
}

.submission-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.submission-field {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.field-label {
    font-size: 0.8rem;
    color: var(--gray-500);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.field-value {
    font-size: 1rem;
    color: var(--gray-900);
    font-weight: 500;
}

.loading {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--gray-500);
}

.empty-state {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--gray-500);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    opacity: 0.5;
}

/* ===========================
   Footer
   =========================== */
.footer {
    text-align: center;
    padding: var(--spacing-lg);
    color: white;
    font-size: 0.9rem;
}

.footer p {
    margin-bottom: var(--spacing-xs);
}

.api-status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.status-indicator {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-weight: 600;
}

.status-indicator::before {
    content: '';
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    animation: pulse 2s ease-in-out infinite;
}

.status-indicator.error::before {
    background: var(--error);
}

/* ===========================
   Spinner
   =========================== */
.spinner {
    animation: rotate 2s linear infinite;
    width: 20px;
    height: 20px;
}

.spinner .path {
    stroke: white;
    stroke-linecap: round;
    animation: dash 1.5s ease-in-out infinite;
}

@keyframes rotate {
    100% { transform: rotate(360deg); }
}

@keyframes dash {
    0% {
        stroke-dasharray: 1, 150;
        stroke-dashoffset: 0;
    }
    50% {
        stroke-dasharray: 90, 150;
        stroke-dashoffset: -35;
    }
    100% {
        stroke-dasharray: 90, 150;
        stroke-dashoffset: -124;
    }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* ===========================
   Animations
   =========================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

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

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-md);
    }
    
    .header {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .logo {
        flex-direction: column;
    }
    
    .card {
        padding: var(--spacing-lg);
    }
    
    .card-header {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .submission-details {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .logo h1 {
        font-size: 1.25rem;
    }
    
    .card-header h2 {
        font-size: 1.5rem;
    }
    
    .stat-value {
        font-size: 2rem;
    }
}