:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --border: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    -webkit-tap-highlight-color: transparent;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1.5rem;
}

.container {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 1rem;
    padding-top: 1rem;
}

.logo-container {
    width: 72px;
    height: 72px;
    background: white;
    border-radius: 18px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    border: 1px solid var(--border);
}

.logo {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    letter-spacing: -0.03em;
}

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

/* Cards & Inputs */
.card,
#upload-view {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    width: 100%;
}

#result-view {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    width: 100%;
    display: none;
}

.input-group {
    margin-bottom: 1.25rem;
}

label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.6rem;
}

input,
select {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: 1rem;
    font-size: 1rem;
    background: #f8fafc;
    color: var(--text-primary);
    transition: border-color 0.2s;
    appearance: none;
}

select {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%2364748b' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 1rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
}

input:focus,
select:focus {
    outline: none;
    border-color: var(--accent);
    background: white;
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border);
    border-radius: 1.25rem;
    padding: 2.5rem 1.5rem;
    text-align: center;
    cursor: pointer;
    background: #f8fafc;
    transition: all 0.2s;
    margin-bottom: 1.5rem;
}

.drop-zone:active,
.drop-zone.dragover,
.drop-zone:hover {
    border-color: var(--accent);
    background: rgba(37, 99, 235, 0.05);
}

.drop-icon {
    width: 48px;
    height: 48px;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.drop-zone:hover .drop-icon {
    color: var(--accent);
}

.drop-text {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.drop-text#filename {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.25rem;
    word-break: break-all;
}

.file-info {
    display: none;
    flex-direction: column;
    align-items: center;
}

/* Buttons */
.btn {
    width: 100%;
    padding: 1.1rem;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 1rem;
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
    transition: transform 0.1s, background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn:active {
    transform: scale(0.98);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}

.copy-btn {
    width: auto;
    padding: 0.6rem 1.25rem;
    font-size: 0.9rem;
    background: var(--text-primary);
    box-shadow: none;
}

/* Progress */
.progress-bar {
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    margin-top: 1.5rem;
    overflow: hidden;
    display: none;
}

.progress-fill {
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.2s ease;
}

/* Result & Download */
.link-box {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    background: #f1f5f9;
    padding: 1rem;
    border-radius: 1rem;
    margin: 1.5rem 0;
    align-items: stretch;
}

.link-input {
    background: white;
    text-align: center;
    font-family: monospace;
    font-size: 0.9rem;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.success-icon {
    width: 64px;
    height: 64px;
    color: var(--success);
    margin: 0 auto 1rem;
    display: block;
}

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

.alert {
    padding: 1rem;
    border-radius: 1rem;
    background: #fef2f2;
    border: 1px solid #fee2e2;
    color: var(--error);
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: 1.5rem;
    display: none;
}

/* Mobile Tweaks */
@media (max-width: 480px) {
    body {
        padding: 1rem;
    }

    h1 {
        font-size: 1.5rem;
    }

    .card {
        padding: 1.25rem;
    }

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