/* File: vat-calculator.css */
body.dark-theme {
    --bg-color: #1a1d21; --surface-color: #2c2f33; --surface-alt-color: #1f2937;
    --primary-text: #e0e0e0; --secondary-text: #a9a9a9; --border-color: #4f545c;
    --accent-color: #16a34a; --accent-color-text: #ffffff;
}
body.light-theme {
    --bg-color: #f8fafc; --surface-color: #ffffff; --surface-alt-color: #f1f5f9;
    --primary-text: #1e293b; --secondary-text: #64748b; --border-color: #e2e8f0;
    --accent-color: #15803d; --accent-color-text: #ffffff;
}
body {
    margin: 0; font-family: 'Kanit', sans-serif; background-color: var(--bg-color);
    color: var(--primary-text); display: flex; justify-content: center; align-items: flex-start;
    min-height: 100vh; padding: 2rem 1rem; box-sizing: border-box; transition: background-color 0.3s, color 0.3s;
}
#theme-toggle {
    position: fixed; top: 20px; right: 20px; background: var(--surface-color); border: 1px solid var(--border-color);
    color: var(--primary-text); width: 40px; height: 40px; border-radius: 50%;
    cursor: pointer; font-size: 18px; display: flex; justify-content: center;
    align-items: center; z-index: 1000; transition: all 0.3s;
}
#theme-toggle:hover { transform: scale(1.1); }
.container { width: 100%; max-width: 42rem; margin: 0 auto; display: flex; flex-direction: column; gap: 2rem; }
.main-card, .info-card {
    background-color: var(--surface-color); border-radius: 1rem;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    padding: 1.5rem; border: 1px solid var(--border-color);
}
@media (min-width: 768px) { .main-card, .info-card { padding: 2rem; } }
body.dark-theme .main-card, body.dark-theme .info-card { box-shadow: 0 4px 15px -3px rgba(0,0,0,0.2); }
.page-header { text-align: center; margin-bottom: 1.5rem; }
.page-header h1 { font-size: 1.875rem; font-weight: 700; color: var(--primary-text); }
.page-header p { color: var(--secondary-text); margin-top: 0.5rem; max-width: 60ch; margin-left: auto; margin-right: auto; }
.tax-form { display: flex; flex-direction: column; gap: 1rem; }
.main-input-group { display: flex; flex-direction: column; gap: 0.5rem; }
.main-input-header { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 0.5rem; }
.main-input-header label { font-weight: 500; color: var(--secondary-text); }
.button-group {
    display: inline-flex; background-color: var(--bg-color); padding: 0.2rem;
    border-radius: 0.5rem; border: 1px solid var(--border-color);
}
.mode-btn {
    padding: 0.25rem 0.75rem; border-radius: 0.375rem; font-size: 0.75rem; font-weight: 600;
    border: none; background-color: transparent; color: var(--secondary-text);
    cursor: pointer; transition: all 0.2s;
}
.mode-btn.active { background-color: var(--accent-color); color: var(--accent-color-text); }
#amountInput {
    width: 100%; padding: 0.75rem 1rem; font-size: 1.5rem; font-weight: 700;
    border: 1px solid var(--border-color); background-color: var(--surface-alt-color);
    color: var(--primary-text); border-radius: 0.5rem;
    transition: all 0.2s; box-sizing: border-box; text-align: right;
}
#amountInput:focus { outline: none; border-color: var(--accent-color); box-shadow: 0 0 0 3px rgba(22, 163, 74, 0.3); }
.rates-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.rate-group { display: flex; flex-direction: column; gap: 0.5rem; }
.rate-group label { font-weight: 500; color: var(--secondary-text); font-size: 0.875rem; }
.rate-group > div { display: flex; }
.rate-group input {
    width: 100%; padding: 0.5rem; text-align: center; font-size: 1rem; font-weight: 600;
    border: 1px solid var(--border-color); background-color: var(--surface-alt-color);
    color: var(--primary-text); border-radius: 0.5rem 0 0 0.5rem;
    -moz-appearance: textfield; transition: all 0.2s;
}
.rate-group input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.rate-group input:focus { outline: none; border-color: var(--accent-color); z-index: 10; position: relative;}
.rate-group span {
    background: var(--bg-color); border: 1px solid var(--border-color); border-left: none;
    padding: 0.5rem 0.75rem; border-radius: 0 0.5rem 0.5rem 0;
}
.button-wrapper { display: flex; gap: 1rem; margin-top: 0.5rem; }
.btn-primary, .btn-secondary {
    flex-grow: 1; font-weight: 700; padding: 0.75rem 1rem; border-radius: 0.5rem; border: 1px solid;
    cursor: pointer; transition: all 0.2s; display: flex; align-items: center; justify-content: center; gap: 0.5rem;
    font-size: 1rem;
}
.btn-primary { background-color: var(--accent-color); color: var(--accent-color-text); border-color: var(--accent-color); }
.btn-primary:hover { opacity: 0.9; }
.btn-secondary { background-color: transparent; color: var(--secondary-text); border-color: var(--secondary-text); }
.btn-secondary:hover { background-color: var(--surface-alt-color); color: var(--primary-text); border-color: var(--primary-text); }
.result-container {
    margin-top: 1.5rem; padding-top: 1.5rem; border-top: 1px solid var(--border-color);
    display: flex; flex-direction: column; gap: 0.75rem;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.result-container.hidden { display: none; }
.result-container { animation: fadeIn 0.5s ease-out; }
.result-container h2 { font-size: 1.25rem; font-weight: 600; margin-bottom: 0.5rem; }
.result-line {
    display: flex; justify-content: space-between; align-items: center;
    padding: 0.75rem 0; border-bottom: 1px dashed var(--border-color);
}
.result-line span:first-child { color: var(--secondary-text); }
.result-line span:last-child { font-weight: 600; font-size: 1.125rem; }
.result-baht-text {
    display: flex; justify-content: space-between; align-items: center;
    text-align: right; font-size: 0.8rem; color: var(--secondary-text);
    padding-right: 0.1rem; margin-top: -0.5rem;
}
.copy-btn {
    background: var(--bg-color); border: 1px solid var(--border-color);
    color: var(--secondary-text); cursor: pointer;
    padding: 0.3rem 0.6rem; margin-left: 0.75rem; border-radius: 6px;
    font-size: 0.9rem; line-height: 1; transition: all 0.2s;
}
.copy-btn:hover { color: var(--primary-text); background-color: var(--surface-color); border-color: var(--accent-color); }
.copy-btn .fa-check { color: var(--accent-color); }
.result-total {
    background-color: var(--surface-alt-color); padding: 1rem; border-radius: 0.5rem;
    margin-top: 0.5rem; display: flex; justify-content: space-between; align-items: center;
}
.result-total span:first-child { font-weight: 700; color: var(--primary-text); line-height: 1.2; }
.result-total span:first-child small { font-weight: 400; color: var(--secondary-text); font-size: 0.75rem; }
.result-total .total-amount { color: var(--accent-color); font-size: 1.875rem; font-weight: 700; }
.info-card h2 { font-size: 1.25rem; font-weight: 600; margin-bottom: 1rem; text-align: center; }
.info-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 640px) { .info-grid { grid-template-columns: 1fr 1fr; } }
.info-item h4 { font-weight: 600; margin-bottom: 0.5rem; color: var(--primary-text); }
.info-item ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 0.5rem; color: var(--secondary-text); font-size: 0.875rem; }
.info-item li { padding-left: 1rem; position: relative; }
.info-item li::before { content: '•'; position: absolute; left: 0; color: var(--accent-color); }
.footer-link { text-align: center; margin-top: 0; }
.footer-link a { color: var(--secondary-text); text-decoration: none; font-size: 0.875rem; }
.footer-link a:hover { text-decoration: underline; }