:root {
    --primary-color: #2563eb; /* Blue 600 */
    --primary-hover: #1d4ed8; /* Blue 700 */
    --bg-color: #f8fafc; /* Slate 50 */
    --form-bg: #ffffff;
    --text-main: #0f172a; /* Slate 900 */
    --text-muted: #475569; /* Slate 600 */
    --border-color: #e2e8f0; /* Slate 200 */
    --border-focus: #3b82f6; /* Blue 500 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 24px;
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: linear-gradient(135deg, #f0f4f8 0%, #e2e8f0 100%);
    color: var(--text-main);
    min-height: 100vh;
    padding: 40px 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.form-container {
    width: 100%;
    max-width: 1100px;
    background-color: var(--form-bg);
    padding: 50px 60px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

/* Subtle top border accent */
.form-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 8px;
    background: linear-gradient(90deg, #3b82f6, #8b5cf6, #ec4899);
}

.header {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
    padding-bottom: 30px;
    border-bottom: 2px solid #f1f5f9;
}

.logo-container {
    margin-bottom: 25px;
    display: flex;
    justify-content: center;
}

.logo-container img {
    max-height: 240px;
    width: auto;
    object-fit: contain;
    transition: var(--transition);
}

.logo-container img:hover {
    transform: scale(1.05);
}

.header h1 {
    color: var(--text-main);
    font-size: 32px;
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.3;
}

.form-section {
    margin-bottom: 50px;
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 40px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.form-section:hover {
    box-shadow: var(--shadow-md);
    border-color: #cbd5e1;
}

.form-section h2 {
    font-size: 20px;
    font-weight: 600;
    color: #ffffff;
    background: linear-gradient(135deg, #1e293b, #334155);
    padding: 14px 24px;
    border-radius: var(--radius-md);
    margin-top: -65px; /* Pull up over the border */
    margin-bottom: 35px;
    display: inline-block;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.2);
    letter-spacing: 0.01em;
}

.sub-section {
    margin-bottom: 35px;
    padding-left: 25px;
    border-left: 4px solid var(--primary-color);
    background: #f8fafc;
    padding: 25px;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    transition: var(--transition);
}

.sub-section:hover {
    background: #f1f5f9;
}

.sub-section h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--primary-hover);
    margin-bottom: 25px;
    display: flex;
    align-items: center;
}

h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border-color);
}

/* Grid Layouts */
.grid-2-col {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.grid-3-col {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.grid-4-col {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.grid-auto-fit {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
}

.col-span-2 {
    grid-column: span 2;
}

/* Forms & Inputs */
.form-group {
    display: flex;
    flex-direction: column;
}

.form-group.flex-row {
    flex-direction: row;
    align-items: center;
    gap: 20px;
}

.flex-grow {
    flex-grow: 1;
}

label {
    font-size: 14.5px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-main);
}

.form-group.flex-row label {
    margin-bottom: 0;
    white-space: nowrap;
}

input[type="text"],
input[type="email"],
input[type="tel"],
textarea {
    padding: 14px 18px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: inherit;
    color: var(--text-main);
    background-color: #fff;
    transition: var(--transition);
    width: 100%;
}

input[type="text"]:hover,
input[type="email"]:hover,
input[type="tel"]:hover,
textarea:hover {
    border-color: #cbd5e1;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="tel"]:focus,
textarea:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.15);
    outline: none;
    background-color: #fdfefe;
}

input[type="text"]::placeholder,
input[type="email"]::placeholder,
input[type="tel"]::placeholder,
textarea::placeholder {
    color: #94a3b8;
}

.form-group.flex-row input[type="text"] {
    width: auto;
    flex: 1;
}

/* Custom Checkboxes */
.checkbox-group label,
.sub-section label {
    display: inline-flex;
    align-items: flex-start;
    font-weight: 500;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
    padding: 6px 0;
    font-size: 15px;
}

.checkbox-group label:hover,
.sub-section label:hover {
    color: var(--text-main);
}

input[type="checkbox"] {
    appearance: none;
    background-color: #fff;
    margin: 0;
    margin-right: 12px;
    margin-top: 3px;
    font: inherit;
    color: currentColor;
    width: 1.3em;
    height: 1.3em;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    display: grid;
    place-content: center;
    cursor: pointer;
    transition: var(--transition);
    flex-shrink: 0;
}

input[type="checkbox"]::before {
    content: "";
    width: 0.75em;
    height: 0.75em;
    clip-path: polygon(14% 44%, 0 65%, 50% 100%, 100% 16%, 80% 0%, 43% 62%);
    transform: scale(0);
    transform-origin: center;
    transition: 120ms transform ease-in-out;
    background-color: white;
}

input[type="checkbox"]:hover {
    border-color: #94a3b8;
}

input[type="checkbox"]:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

input[type="checkbox"]:checked::before {
    transform: scale(1);
}

input[type="checkbox"]:focus {
    outline: max(2px, 0.15em) solid rgba(59, 130, 246, 0.25);
    outline-offset: max(2px, 0.15em);
}

.input-with-checkbox {
    display: flex;
    align-items: center;
    gap: 15px;
    grid-column: span 2;
}

.input-with-checkbox input[type="text"] {
    flex: 1;
}

.inline-checkboxes {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-left: 20px;
}

.inline-checkboxes label {
    margin: 0;
}

.input-stacked {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.inline-input {
    display: flex;
    align-items: center;
    gap: 15px;
}

.inline-input label {
    margin-bottom: 0;
    min-width: 160px;
}

.inline-input input {
    flex: 1;
}

.specs-grid {
    align-items: center;
    row-gap: 25px;
}

/* Submit Button */
.actions {
    margin-top: 60px;
    text-align: center;
}

.submit-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, #4f46e5 100%);
    color: white;
    border: none;
    padding: 18px 50px;
    font-size: 18px;
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 10px 15px -3px rgba(37, 99, 235, 0.3), 0 4px 6px -2px rgba(37, 99, 235, 0.2);
    letter-spacing: 0.5px;
}

.submit-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 20px 25px -5px rgba(37, 99, 235, 0.4), 0 10px 10px -5px rgba(37, 99, 235, 0.2);
}

.submit-btn:active {
    transform: translateY(1px);
    box-shadow: 0 5px 10px -3px rgba(37, 99, 235, 0.3);
}

/* Responsive adjustments */
@media (max-width: 1024px) {
    .grid-4-col {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    body {
        padding: 15px 10px;
        background: var(--bg-color); /* Simpler background on mobile */
    }
    
    .form-container {
        padding: 40px 20px 30px;
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-md);
    }

    .form-section {
        padding: 30px 15px 20px;
        margin-bottom: 35px;
    }

    .form-section h2 {
        font-size: 18px;
        margin-top: -45px;
        margin-bottom: 25px;
        padding: 10px 20px;
    }

    .grid-2-col, .grid-3-col, .grid-4-col {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .form-group.flex-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .form-group.flex-row input[type="text"] {
        width: 100%;
    }

    .col-span-2 {
        grid-column: span 1;
    }
    
    .inline-checkboxes {
        margin-left: 0;
        margin-top: 5px;
    }
    
    .sub-section {
        padding: 20px 15px;
        border-radius: var(--radius-md);
        border-left: none;
        border-top: 4px solid var(--primary-color);
        margin-bottom: 25px;
    }

    .header h1 {
        font-size: 24px;
    }

    .input-with-checkbox {
        grid-column: span 1;
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .input-with-checkbox input[type="text"] {
        width: 100%;
    }
    
    .inline-input {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    
    .inline-input label {
        min-width: auto;
    }

    .submit-btn {
        width: 100%;
        padding: 16px;
    }
}