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

body {
    font-family: 'Montserrat', sans-serif;
    background-color: #f5f5f5;
    padding: 20px 0;
}

.form-wrapper {
    padding: 40px 0;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==================== ЦВЕТА КОМПАНИЙ ====================  */
:root {
    --accent: #2196F3;
    --accent-hover: #1976D2;
    --accent-shadow: rgba(33, 150, 243, 0.3);
    --accent-light: rgba(33, 150, 243, 0.1);
}

body.theme-happy-student {
    --accent: #2196F3;
    --accent-hover: #1976D2;
    --accent-shadow: rgba(33, 150, 243, 0.3);
    --accent-light: rgba(33, 150, 243, 0.1);
}

body.theme-diplom-top {
    --accent: #FF9800;
    --accent-hover: #F57C00;
    --accent-shadow: rgba(255, 152, 0, 0.3);
    --accent-light: rgba(255, 152, 0, 0.1);
}

body.theme-studik {
    --accent: #4CAF50;
    --accent-hover: #45a049;
    --accent-shadow: rgba(76, 175, 80, 0.3);
    --accent-light: rgba(76, 175, 80, 0.1);
}

/* ==================== ТАБЫ ====================  */
.payment-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    border-bottom: 2px solid #e0e0e0;
    flex-wrap: wrap;
}

.tab-button {
    padding: 12px 24px;
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-family: 'Montserrat', sans-serif;
    font-size: 16px;
    font-weight: 600;
    color: #666;
    transition: all 0.3s ease;
    position: relative;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: -2px;
}

.tab-button:hover {
    color: #333;
    background-color: rgba(0, 0, 0, 0.02);
}

.tab-button.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

.tab-icon {
    font-size: 20px;
}

/* ==================== КОНТЕНТ ТАБОВ ====================  */
.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==================== ФОРМА ====================  */
.invoice-form {
    background: white;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 25px;
}

.form-group h2 {
    font-size: 14px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-family: 'Montserrat', sans-serif;
    font-size: 14px;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-light);
}

.form-group input::placeholder {
    color: #999;
}

select {
    cursor: pointer;
}

/* ==================== КНОПКА ОТПРАВКИ ====================  */
.btn-submit {
    width: 100%;
    padding: 15px;
    background-color: var(--accent);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 20px;
    font-family: 'Montserrat', sans-serif;
}

.btn-submit:hover {
    background-color: var(--accent-hover);
    box-shadow: 0 4px 12px var(--accent-shadow);
    transform: translateY(-2px);
}

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

/* ==================== РЕЗУЛЬТАТЫ ====================  */
.form-result {
    margin-top: 25px;
    padding: 20px;
    border-radius: 4px;
    min-height: auto;
}

.loading {
    text-align: center;
    color: #666;
    font-size: 16px;
    padding: 20px;
    background-color: #f0f0f0;
    border-radius: 4px;
    border-left: 4px solid var(--accent);
}

.success-message {
    background-color: #d4edda;
    border: 1px solid #c3e6cb;
    color: #155724;
    padding: 20px;
    border-radius: 4px;
    border-left: 4px solid #28a745;
}

.success-message p {
    margin-bottom: 15px;
    line-height: 1.5;
}

.success-message p:last-child {
    margin-bottom: 0;
}

.success-message a {
    color: #155724;
    font-weight: 600;
    text-decoration: underline;
    word-break: break-all;
}

.success-message a:hover {
    color: #0c5c1d;
}

.error-message {
    background-color: #f8d7da;
    border: 1px solid #f5c6cb;
    color: #721c24;
    padding: 20px;
    border-radius: 4px;
    border-left: 4px solid #dc3545;
}

.error-message p {
    margin-bottom: 15px;
    line-height: 1.5;
}

.error-message p:last-child {
    margin-bottom: 0;
}

.error-message a {
    color: #721c24;
    text-decoration: underline;
}

/* ==================== КНОПКИ В РЕЗУЛЬТАТАХ ====================  */
.btn-copy,
.btn-invoice {
    display: inline-block;
    padding: 10px 20px;
    margin-top: 10px;
    margin-right: 10px;
    background-color: var(--accent);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    font-family: 'Montserrat', sans-serif;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn-copy:hover,
.btn-invoice:hover {
    background-color: var(--accent-hover);
    box-shadow: 0 4px 8px var(--accent-shadow);
}

.btn-invoice {
    display: inline-block;
    text-decoration: none;
}

/* ==================== АДАПТИВНОСТЬ ====================  */
@media (max-width: 768px) {
    .invoice-form {
        padding: 25px;
    }

    .payment-tabs {
        margin-bottom: 20px;
    }

    .tab-button {
        padding: 10px 16px;
        font-size: 14px;
    }

    .form-group {
        margin-bottom: 20px;
    }

    .form-group input,
    .form-group select {
        padding: 10px 12px;
        font-size: 13px;
    }

    .btn-submit {
        padding: 12px;
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .invoice-form {
        padding: 20px;
    }

    .payment-tabs {
        flex-direction: column;
        gap: 0;
        border-bottom: 1px solid #e0e0e0;
    }

    .tab-button {
        width: 100%;
        justify-content: center;
        padding: 12px;
        border-bottom: 2px solid #e0e0e0;
        border-right: none;
        margin-bottom: 0;
    }

    .tab-button.active {
        border-right: none;
    }

    .form-wrapper {
        padding: 20px 0;
    }

    .form-group {
        margin-bottom: 18px;
    }

    .form-group h2 {
        font-size: 12px;
        margin-bottom: 8px;
    }

    .form-group input,
    .form-group select {
        padding: 10px;
        font-size: 12px;
    }

    .form-result {
        margin-top: 20px;
        padding: 15px;
    }
}

/* ==================== GRID LAYOUT ====================  */
.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.col-12 {
    flex: 0 0 100%;
    padding: 0 15px;
}

/* Утилиты */
small {
    font-size: 12px;
    color: #666;
}

strong {
    font-weight: 700;
}