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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #8b5cf6;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    padding: 2rem 1rem;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    color: white;
    flex-wrap: wrap;
    gap: 1rem;
}

.title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.download-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.download-btn .icon {
    width: 18px;
    height: 18px;
}

.subtitle {
    font-size: 1.125rem;
    opacity: 0.95;
    font-weight: 300;
}

/* Main Content */
.main {
    background: var(--surface);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-xl);
}

/* Form Section */
.form-section {
    margin-bottom: 2.5rem;
}

.shorten-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    flex: 1;
}

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

.input-field {
    padding: 1rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all 0.3s ease;
    background: var(--surface);
    color: var(--text-primary);
    font-family: inherit;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-field::placeholder {
    color: var(--text-secondary);
}

.input-primary {
    font-size: 1.125rem;
}

.submit-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    margin-top: 0.5rem;
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.submit-btn .icon {
    width: 20px;
    height: 20px;
}

/* Status Message */
.status-message {
    margin-bottom: 1.5rem;
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    display: none;
    animation: slideIn 0.3s ease;
}

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

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

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

/* List Section */
.list-section {
    margin-top: 2.5rem;
}

.list-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

.link-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

.link-item {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    cursor: pointer;
    transition: all 0.3s ease;
    animation: fadeIn 0.3s ease;
}

.link-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.link-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.link-title::before {
    content: '🔗';
    font-size: 1rem;
}

.link-info {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 1rem;
    flex-wrap: wrap;
}

.link-details {
    flex: 1;
}

.link-url {
    font-size: 0.875rem;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
    word-break: break-all;
}

.link-memo {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
}

.link-date {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: right;
}

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.2s ease;
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--surface);
    border-radius: var(--radius-xl);
    padding: 2rem;
    max-width: 500px;
    width: 90%;
    position: relative;
    animation: slideUp 0.3s ease;
    box-shadow: var(--shadow-xl);
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

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

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.modal-body {
    margin-top: 1rem;
}

.short-url-display {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.short-url-input {
    flex: 1;
    padding: 1rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--background);
    color: var(--primary-color);
    font-weight: 600;
    min-width: 200px;
}

.copy-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.copy-btn:hover {
    background: var(--primary-hover);
    transform: scale(1.05);
}

.copy-btn .icon {
    width: 18px;
    height: 18px;
}

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

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

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

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding: 1rem;
    }

    .header {
        justify-content: center;
        text-align: center;
    }

    .title {
        font-size: 2rem;
        width: 100%;
    }

    .download-btn {
        font-size: 0.875rem;
        padding: 0.625rem 1.25rem;
    }

    .main {
        padding: 1.5rem;
        border-radius: var(--radius-lg);
    }

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

    .link-info {
        flex-direction: column;
        align-items: flex-start;
    }

    .link-date {
        text-align: left;
    }

    .modal-content {
        width: 95%;
        padding: 1.5rem;
    }

    .short-url-display {
        flex-direction: column;
    }

    .short-url-input {
        width: 100%;
    }

    .copy-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .title {
        font-size: 1.75rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .main {
        padding: 1.25rem;
    }

    .submit-btn {
        font-size: 1rem;
    }
}