/* 🎨 CSS VARIABLES (LIGHT & DARK THEME) */
:root {
    --bg-body: #f1f5f9;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    
    /* Headers & Title */
    --q-bg: #e2e8f0;
    --q-text: #1e293b;
    --q-border: #1d4ed8;

    /* Option Cards */
    --opt-bg: #f8fafc;
    --opt-border: #cbd5e1;
    --opt-text: #334155;
    --opt-hover-bg: #f1f5f9;
    --opt-hover-border: #94a3b8;
    --opt-checked-bg: #eff6ff;
    --opt-checked-border: #1d4ed8;
    --opt-checked-text: #1e3a8a;

    /* Inputs & Selects */
    --input-bg: #ffffff;
    --input-border: #cbd5e1;
    --input-text: #0f172a;

    /* Progress Bar & Buttons */
    --progress-bg: #cbd5e1;
    --progress-fill: linear-gradient(90deg, #1d4ed8, #2563eb);
    --btn-bg: #1d4ed8;
    --btn-bg-hover: #1e40af;
    --btn-text: #ffffff;
}

[data-theme="dark"] {
    --bg-body: #0f172a;
    --bg-card: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;

    /* Headers Dark */
    --q-bg: #0f172a;
    --q-text: #93c5fd;
    --q-border: #3b82f6;

    /* Option Cards Dark */
    --opt-bg: #0f172a;
    --opt-border: #334155;
    --opt-text: #f1f5f9;
    --opt-hover-bg: #1e293b;
    --opt-hover-border: #475569;
    --opt-checked-bg: #1e3a8a;
    --opt-checked-border: #3b82f6;
    --opt-checked-text: #93c5fd;

    /* Inputs Dark */
    --input-bg: #0f172a;
    --input-border: #475569;
    --input-text: #f8fafc;

    /* Progress Bar & Buttons Dark */
    --progress-bg: #334155;
    --progress-fill: linear-gradient(90deg, #3b82f6, #60a5fa);
    --btn-bg: #2563eb;
    --btn-bg-hover: #1d4ed8;
    --btn-text: #ffffff;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 12px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Main Container Card */
.container {
    width: 100%;
    max-width: 580px;
    background: var(--bg-card);
    padding: 20px 18px;
    border-radius: 14px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
    transition: background 0.3s ease;
}

/* ☀️/🌙 LIGHT & DARK MODE TOGGLE BUTTON */
.theme-toggle-container {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 12px;
}

.theme-toggle-btn {
    background: var(--opt-bg);
    border: 1px solid var(--opt-border);
    color: var(--text-main);
    padding: 6px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.theme-toggle-btn:hover {
    transform: scale(1.05);
}

.theme-toggle-btn #themeIcon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Header & Title */
.poll-title {
    font-size: 19px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 14px;
    text-align: center;
    line-height: 1.3;
}

/* Progress Bar */
.progress-container {
    width: 100%;
    height: 6px;
    background: var(--progress-bg);
    border-radius: 10px;
    margin-bottom: 16px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: var(--progress-fill);
    border-radius: 10px;
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Steps Transition */
.question-step {
    display: none;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.question-step.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* 🏷️ ΤΙΤΛΟΙ ΕΡΩΤΗΣΕΩΝ */
.question-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--q-text);
    margin-bottom: 12px;
    line-height: 1.35;
    background: var(--q-bg);
    padding: 10px 14px;
    border-radius: 8px;
    border-left: 5px solid var(--q-border);
}

/* 🗳️ ΚΑΡΤΕΣ ΑΠΑΝΤΗΣΕΩΝ */
.option-card {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: var(--opt-bg);
    border: 1.5px solid var(--opt-border);
    border-radius: 8px;
    margin-bottom: 8px;
    font-size: 15px;
    font-weight: 500;
    color: var(--opt-text);
    cursor: pointer;
    user-select: none;
    transition: all 0.15s ease-in-out;
}

.option-card:hover {
    background: var(--opt-hover-bg);
    border-color: var(--opt-hover-border);
}

.option-card:has(input:checked) {
    background: var(--opt-checked-bg);
    border-color: var(--opt-checked-border);
    color: var(--opt-checked-text);
    font-weight: 600;
}

.option-card input[type="radio"],
.option-card input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--q-border);
    cursor: pointer;
}

/* Form Controls (Text, Select, etc.) */
textarea, input[type="text"], input[type="number"], input[type="date"], 
input[type="time"], input[type="email"], input[type="tel"], input[type="url"], select {
    width: 100%;
    padding: 10px 12px;
    font-size: 15px;
    color: var(--input-text);
    background: var(--input-bg);
    border: 1.5px solid var(--input-border);
    border-radius: 8px;
    box-sizing: border-box;
    transition: all 0.2s ease;
    outline: none;
    margin-bottom: 6px;
}

textarea:focus, input:focus, select:focus {
    border-color: var(--q-border);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

/* Rating Stars */
.rating-stars {
    display: flex;
    justify-content: center;
    gap: 10px;
    font-size: 36px;
    cursor: pointer;
    user-select: none;
    margin: 12px 0;
}

.rating-stars .star {
    color: #cbd5e1;
    transition: transform 0.15s ease, color 0.15s ease;
}

.rating-stars .star.hover,
.rating-stars .star.selected,
.rating-stars .star.active {
    color: #f59e0b;
}

/* Navigation Button */
.btn-nav {
    width: 100%;
    padding: 12px;
    background: var(--btn-bg);
    color: var(--btn-text);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 700;
    margin-top: 14px;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.15);
    transition: all 0.15s ease;
}

.btn-nav:hover {
    background: var(--btn-bg-hover);
}

.btn-nav:active {
    transform: translateY(1px);
}

/* 🎯 QR CODE CONTAINER & IMAGE (Ideal for Presentation/Projector) */
.qr-container {
    text-align: center !important;
    margin: 10px auto 20px auto !important;
    width: 100% !important;
}

.qr-title {
    font-size: 15px !important;
    font-weight: 600 !important;
    color: var(--text-muted) !important;
    margin-bottom: 8px !important;
}

.qr-container img,
.qr-container svg,
.qr-image {
    width: 360px !important;            /* Μεγάλο μέγεθος για προβολέα / αίθουσα */
    height: 360px !important;
    max-width: 100% !important;          /* Προσαρμόζεται αυτόματα αν η οθόνη είναι πολύ μικρή */
    max-height: 360px !important;
    border-radius: 10px !important;
    border: 2px solid var(--opt-border) !important;
    padding: 8px !important;
    background: #ffffff !important;      /* Πάντα λευκό φόντο για μέγιστο contrast */
    display: inline-block !important;
    box-sizing: border-box !important;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08) !important;
}

/* Thank you Screen */
.thank-you-screen {
    display: none;
    text-align: center;
    padding: 20px 10px;
}

.thank-you-screen .icon-circle {
    width: 64px;
    height: 64px;
    background: #dcfce7;
    color: #15803d;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    margin: 0 auto 14px;
}

.thank-you-screen h3 {
    color: var(--text-main);
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 6px;
}

.thank-you-screen p {
    color: var(--text-muted);
    font-size: 14px;
}